Nadine Dorries, who attended a reception with the PM and his fiancé Carrie Symonds in Downing Street last Thursday,said in a statement on Tuesday that she had been diagnosed with the virus and is in self-isolation.
A government source said on Wednesday Johnson would not be tested, as he was displaying no symptoms and had not come in close contact with Dorries at the event. They pointed out the current medical advice claims you would need to be within 2 meters of someone carrying the infection, which Johnson at no point was.
Health officials are now racing to trace those who have had contact with Dorries, who has kept a busy diary of engagements in and around the UK's political center.
"I can confirm I have tested positive for Coronavirus," Dorries, a junior health minister, said in a statement released through the Department of Health. "As soon as I was informed I took all the advised precautions and have been self-isolating at home."
"It's been pretty rubbish but I hope I'm over the worst of it now," Dorries added on Twitter. "More worried about my 84yo mum who is staying with me and began with the cough today. She is being tested tomorrow."
Her diagnosis also raises questions about whether Britain's Parliament will need to be temporarily shut down. Officials confirmed to CNN that there are still no plans to take such a step.
Dorries was at an International Women's Day event in Downing Street last week alongside the Prime Minister and his partner, several other MPs and staffers.
The effort to identify all those who have been in contact with Dorries has led officials to advise another lawmaker, Labour's Rachael Maskell, to go into self-isolation after she met with the minister.
"Thankfully I am asymptomatic. It is so important that we all follow all public health advice," Maskell said on Twitter Wednesday.
Dorries also sent a message to the Conservative MPs' WhatsApp group telling them that a member of her staff has fallen ill, PA Media news agency reported.
The UK's health secretary Matt Hancock, whose department has been leading Britain's coronavirus response, told lawmakers on Monday that he was against closing down Parliament as the outbreak spreads.
"Parliamentary scrutiny is incredibly important and I will do all that I can to ensure that Parliament remains open," Hancock said. Most MPs are expected on the estate on Wednesday, as the UK's annual budget is revealed.
Dorries' diagnosis comes as the UK's coronavirus cases near 400. Six people have died of the virus in the country.
Johnson on Monday set out his government's plan to tackle the outbreak, announcing a £46 million ($59 million) funding package to fight the spread.
But Johnson has resisted calls to follow a more drastic approach such as introducing a lockdown and banning public events.
Nadine Dorries, who attended a reception with the Prime Minister and his fiancé Carrie Symonds in Downing Street last Thursday,said in a statement on Tuesday that she had been diagnosed with the virus and is in self-isolation.
Health officials are now racing to trace those who have had contact with Dorries, who has kept a busy diary of engagements in and around the UK's political center.
"I can confirm I have tested positive for Coronavirus," Dorries, a junior health minister, said in a statement released through the Department of Health. "As soon as I was informed I took all the advised precautions and have been self-isolating at home."
"It's been pretty rubbish but I hope I'm over the worst of it now," Dorries added on Twitter. "More worried about my 84yo mum who is staying with me and began with the cough today. She is being tested tomorrow."
Her diagnosis also raises questions about whether Britain's Parliament will need to be temporarily shut down. Officials confirmed to CNN that there are still no plans to take such a step.
Dorries was at an International Women's Day event in Downing Street last week alongside the Prime Minister and his partner, several other MPs and staffers.
The effort to identify all those who have been in contact with Dorries has led officials to advise another lawmaker, Labour's Rachael Maskell, to go into self-isolation after she met with the minister.
"Thankfully I am asymptomatic. It is so important that we all follow all public health advice," Maskell said on Twitter Wednesday.
Dorries also sent a message to the Conservative MPs' WhatsApp group telling them that a member of her staff has fallen ill, PA Media news agency reported.
The UK's health secretary Matt Hancock, whose department has been leading Britain's coronavirus response, told lawmakers on Monday that he was against closing down Parliament as the outbreak spreads.
"Parliamentary scrutiny is incredibly important and I will do all that I can to ensure that Parliament remains open," Hancock said. Most MPs are expected on the estate on Wednesday, as the UK's annual budget is revealed.
Dorries' diagnosis comes as the UK's coronavirus cases near 400. Six people have died of the virus in the country.
Johnson on Monday set out his government's plan to tackle the outbreak, announcing a £46 million ($59 million) funding package to fight the spread.
But Johnson has resisted calls to follow a more drastic approach such as introducing a lockdown and banning public events.
The Bank of England has announced an emergency cut in interest rates to shore up the economy amid the coronavirus outbreak.
Policymakers reduced rates from 0.75% to 0.25%, taking borrowing costs back down to the lowest level in history.
The Bank said it would also free up billions of pounds of extra lending power to help banks support firms.
It comes as the chancellor is expected to announce further measures to support growth and jobs in the Budget later.
'Maximum impact'
Mark Carney, the outgoing governor of the Bank of England, said policymakers had seen a "sharp fall in trading conditions", including spending on non-essential goods.
"The Bank of England's role is to help UK businesses and households manage through an economic shock that could prove large and sharp, but should be temporary," he said.
He said the Bank's co-ordinated action on Budget day was designed to have "maximum impact".
Mr Carney stressed that the economic damage caused by the coronavirus remained unclear. However, he suggested that the UK economy could shrink in the coming months.
He said early evidence from China suggested that the world's second largest economy was on course to contract in the first quarter.
Other nations were experiencing a "similar shift", he said.
"I would emphasise the direction is clear, though the orders of magnitude are still to be determined."
While the Bank's last emergency rate cut was in October 2008, Mr Carney said the virus was unlikely to inflict the damage seen during the financial crisis.
"There is no reason for it to be as bad as 2008 if we act as we have, and if there is that targeted support," he said.
Virus spread
The emergency rate cut comes as a sixth person died from the virus in the UK, which has a total of 382 cases.
The latest person to die was a man in his early 80s who had underlying health conditions.
A number of Arsenal players are in self-isolation after coming into contact with Olympiakos owner Evangelos Marinakis, who tested positive for the virus..
Chancellor Rishi Sunak has pledged to help the UK battle the impact of the coronavirus, saying the NHS will get "whatever resources it needs" during the crisis, while he is also expected to unveil measures to boost the self-employed and small businesses who are left out of pocket.
The sudden cut in the Bank rate will immediately reduce the mortgage bill of a minority of homeowners. Others will have to wait to see how their home loan provider reacts at a time when mortgage rates are already at very low levels.
Little will change for savers, who have had to endure years of low returns anyway. They may take heart from the fact this is a temporary measure from the Bank.
Most people are, of course, savers and borrowers.
As well as concern over their physical health from coronavirus, their financial health will primarily depend on their job.
This emergency action is clearly designed to help protect businesses, particularly small and medium-sized ones, and in turn the employment of millions of people.
The interest rate cut was part of a package of measures introduced by the Bank to support the economy.
It also announced a new £100bn scheme to help ensure households and businesses - particularly small and medium-sized firms - benefit from the reduction in interest rates.
The Bank of England said other changes would free up an additional £190bn for banks to lend.
It said the package of measures would "help UK businesses and households bridge across the economic disruption that is likely to be associated with Covid-19".
The Bank said it expected UK economic activity to "weaken materially" over the coming months, but it was ready to take "all further necessary steps to support the UK economy".
"These measures will help to keep firms in business and people in jobs and help prevent a temporary disruption from causing longer-lasting economic harm."
Initially, the pound fell against both the euro and the dollar in reaction to the rate cut, but then rebounded.
Share markets reacted positively, with the FTSE 100 rising more than 2% in early trading.
The dramatic emergency rate cut will dominate the headlines, but it is the overall package of measures which the departing Bank of England governor Mark Carney will stress as a support for the economy in this extraordinary coronavirus crisis.
The key target of this move is the cashflow of small and medium-sized businesses, which could be hit by a combination of slumping demand, trade difficulties and staff absence.
The Bank and Treasury agree that this will be a temporary shock. The aim, therefore, is to prevent unnecessary permanent economic scars. Alongside Budget measures, it is designed as a bridge beyond the virus.
So the Bank's base rate is slashed to its record low, first reached in the aftermath of the EU referendum. But as important is the new TFSME - the "Term Funding scheme with additional incentives for Small and Medium-sized Enterprises".
This proved rather successful after the EU referendum, and the aim is to get the banks to pass on the rate cut in full to businesses, particularly small and medium-sized firms, which face the greatest pressure to cut staff or hours in a crisis.
The deployment of the counter-cyclical buffer, lowering capital requirements for banks by 2%, was designed for exactly this sort of rainy day. It should provide the firepower for banks to boost lending well above current lending levels.
To be clear, coronavirus is unique and highly unpredictable. There is a fundamental problem of people and businesses not being able to function because of the measures to contain the virus. The message from the Bank is that the banking system is fully padded up to help businesses get through this.
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Christie Elan-Cane was urging the Home Office to allow an "X" gender option, alongside male and female. They had argued the UK's current passport process is "unacceptable," and breaches international human rights law.
Elan-Cane's original legal challenge was rejected last year by London's High Court, and on Tuesday senior judges dismissed the appeal.
"I regret to inform that the Appeal Court has ruled in the UK government's favor in a judgment handed down this morning," Elan-Cane said in a statement on Twitter Tuesday, adding that they intended to seek permission for the case to be heard at the Supreme Court, which is the final court of appeal in the UK.
A handful of countries, including Germany, Australia and Canada, already offer a third option, other than male or female, on their passports.
"X" is accepted as a gender entry on machine-readable travel documents, alongside "M" and "F," under standards set by the International Civil Aviation Organization.
''Legitimate identity is a fundamental human right but non-gendered people are treated as though we have no rights," Elan-Cane said in a statement Tuesday. "It is unacceptable that someone who defines as neither male nor female is forced to declare an inappropriate gender in order to obtain a passport."
"This decision is devastating to me. It is bad news for everyone who cannot obtain a passport without the requirement imposed by the UK government that they should collude in their own social invisibility."
Clifford Chance, the law firm representing Elan-Cane on a pro bono basis, said that the court found the UK government's policy, which requires an "M" or "F" gender marker was not unlawful.
However, the court also held that the European Convention on Human Rights "guarantees a right to respect for non-gendered identity," the law firm added.
A spokesperson for the Home Office told CNN: "We welcome the Court of Appeal's judgment."
The decision to delay closing schools and introduce other strict measures to combat coronavirus has been defended by England's deputy chief medical officer.
Dr Jenny Harries said experts are assessing new cases on an hourly basis to achieve a "balanced response".
It comes as a man in his early 80s became the sixth person with the virus to die in the UK.
Meanwhile, many airlines cut thousands of flights, including to and from Italy, in the wake of the outbreak.
Northern Ireland announced four more cases, bringing its total to 16, and Scotland confirmed another four cases, increasing its number to 27.
The latest death happened on Monday evening and was a man with underlying health conditions who was being looked after at Watford General Hospital, the West Hertfordshire Hospitals NHS Trust said.
He caught the virus in the UK and officials are trying to trace who he was in contact with, the country's chief medical adviser Prof Chris Whitty said.
Earlier, Dr Harries said the vast majority of those diagnosed with coronavirus in Britain are "pretty well" but that they may "feel a bit rough for a few days".
She told BBC Breakfast new government measures could follow as UK cases begin to rise rapidly over the next two weeks.
She added that people with flu-like symptoms will be advised to self-isolate within 10 to 14 days and, at the same time, significant increases in the number of cases are likely to begin.
Dr Harries said cancelling big outdoor events like football matches would not necessarily be a decision supported by science.
"The virus will not survive very long outside," she said. "Many outdoor events, particularly, are relatively safe."
Italy's extended quarantine measures require residents to stay home, seek permission for essential travel, and justify leaving the country.
Son speaks of father's death
On Sunday, a 60-year-old man from Greater Manchester became the third person to die after contracting coronavirus after recently visiting northern Italy.
The son said his father fell ill "instantly" after returning to the UK at the end of February. He turned up at a local health centre for a routine appointment and, when he said he had been to Italy, "panic broke out".
His father was taken to North Manchester General Hospital and the rest of the family were told to self-isolate - with Public Health England sending daily texts asking if they are showing symptoms.
"Since we cannot go outside we regularly called the ward where he was ill," the man's son told BBC Bengali. "And on a daily basis and we asked them how he was. They did not allow me to speak to him directly.
"The first couple of days he was fairly stable but after that they were saying his blood was not oxygenated enough. Also his heartbeat was not stable either."
The son said they received a phone call from the hospital saying his father - who had underlying conditions including arthritis, heart problems, and cholesterol - had died.
"Obviously I could not believe it because two months ago this thing didn't even exist and today it took away my father.
"It took me quite a long time to process the whole thing that I'm not going to be able to see him anymore."
British Airways has cancelled all of its flights to and from Italy until 4 April, and has asked staff to take voluntary unpaid leave.
Ryanair will cancel all its flights to and from Italy from Saturday until 8 April, while Easyjet cancelled the majority of its flights to and from the country and Jet2 cancelled its Italian routes until 26 April.
BA said customers due to fly to or from Italy before 4 April can rebook to a later date until the end of May, move their destination to Geneva or Zurich, or receive a full refund.
A Foreign Office spokesman said: "The advice is that anyone who arrives from Italy subsequent to the Italian government decision should now self-isolate for 14 days."
Downing Street said Italians arriving in the UK were being given the same advice as Britons to self-isolate and that the government had facilities available to accommodate them.
Meanwhile airline Norwegian, which operates from several UK airports, said it was cutting 3,000 flights and reducing staff numbers after a fall in demand it attributed to coronavirus.
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The NHS has unveiled a range of measures as part of its response to try to stop fake news being spread about coronavirus on the internet.
Searches for "coronavirus" on Google, Facebook and YouTube will now promote information from the National Health Service or the World Health Organization.
Health Secretary Matt Hancock said the actions meant the public could access accurate health information "which is more crucial than ever as we continue our response to coronavirus".
Asked about statutory sick pay for workers who are not currently eligible, Health Secretary Matt Hancock told MPs that "whatever the status of people" who are employed, the government will "ensure that they will get the support so they're not penalised for doing the right thing".
On Monday, health officials said people who showed "even minor" signs of respiratory tract infections or a fever would - within the next 14 days - be told to self-isolate for a week in an effort to tackle the outbreak.
The environment department, Defra, said by allowing night-time deliveries - currently restricted to avoid disturbing locals - stock would be able to move more quickly from warehouses to shelves.
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Meanwhile, US authorities are expected to fly home Britons who were on board the virus-hit Grand Princess cruise ship later, according to the Foreign Office.
However, one of the Britons on board, Jackie Bissell, told BBC Radio 4's Today programme she had yet to hear from the ship's captain about her departure.
"They haven't said anything about when we can go," she said. "It's very unnerving to be left out here when we don't know what's going to happen."
Elsewhere, crowds exceeding 60,000 are expected on all four days of horse racing's Cheltenham Festival, which starts on Tuesday afternoon.
It comes after Culture Secretary Oliver Dowden said there was no reason to cancel such events due to coronavirus, although many other sporting fixtures, including the Six Nations and Formula One, have been affected.
What are your experiences relating to the coronavirus outbreak? Share your experiences by emailing haveyoursay@bbc.co.uk.
Please include a contact number if you are willing to speak to a BBC journalist. You can also contact us in the following ways:
People who show "even minor" signs of respiratory tract infections or a fever will soon be told to self-isolate in an effort to tackle the coronavirus outbreak.
The UK government's chief medical adviser said the change in advice could happen within the next 10 to 14 days.
Five people have now died from coronavirus in the UK.
It comes as the Foreign Office warned British residents against all but essential travel to Italy.
People will be asked to self-isolate for seven days after showing mild symptoms under the new approach, the UK's chief medical adviser Prof Chris Whitty said.
All intensive care patients will now be tested for the virus, he said - as well as anyone in hospital with a respiratory infection.
It comes as two more deaths in the UK were announced.
Both patients - who were in hospital in Wolverhampton and Carshalton, south London, respectively - were in their 70s and had underlying health conditions.
In a joint press conference with Prof Whitty in Downing Street, Prime Minister Boris Johnson also suggested the elderly and vulnerable could be asked to stay home in the near future, with further steps set out "in the days and weeks ahead".
He said that the more the peak of the spread could be delayed to summer, "the better the NHS will be able to manage".
Dramatic falls led to it being called Black Monday, with a nearly 8% drop in London's FTSE 100 wiping some £125bn off the value of major UK firms.
In the US the major stock indexes fell so sharply as the market opened that trading was halted for 15 minutes to curb panicky selling.
Labour's shadow chancellor John McDonnell called on Chancellor Rishi Sunak to urgently "reassure the public and markets".
Mr McDonnell said Mr Sunak must use Wednesday's Budget to make clear the government would do "everything necessary" to support the economy as the virus spreads.
"In these circumstances you need to be fast in demonstrating that there is a clear plan," he said.
A European Union expert said the UK had only a "few days" to implement measures to prevent an outbreak like the one in Italy.
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London mayoral candidate Rory Stewart has called the UK government's measures "half-hearted".
Mr Stewart, a former Conservative minister, said the UK should act "much more aggressively", adding: "The government has made a serious mistake today... schools should be shut now."
But the prime minister said the government must "take the right decisions at the right time".
Meanwhile, universal credit claimants who have to self-isolate will not be sanctioned, a work and pensions minister has confirmed.
What's been cancelled?
A number of public and sporting events have been cancelled or postponed due to fears large gatherings could further spread the virus.
Dublin's annual St Patrick's Day parade, the largest on the island of Ireland, was cancelled on Monday, as the total number of positive cases in the Republic rose to 21
The France v Ireland Six Nations rugby game - which was set to be held in Paris on Saturday - has been postponed
England's Six Nations games against Italy on 14 and 15 March have been postponed - affecting the men's, women's and under-20s contests. It came after the Italian government ordered all sporting fixtures to be played behind closed doors until 3 April in a bid to contain the outbreak
Ireland's Six Nations fixtures at home against Italy on 7 and 8 March were postponed last week
The Indian Wells tennis tournament, one of the most prestigious outside of the Grand Slams, has been cancelled, with some players having already arrived in California for the event
The London Book Fair, one of the UK's largest book events, was called off after a number of publishers and agencies pulled out of the event
Mr Johnson said the government is preparing to move to the second phase - "delay" - which will seek to push back the peak of the epidemic to the summer, when there will be less pressure on the NHS.
Prof Whitty said introducing measures "too early" could become problematic as "anything we do, we have got to be able to sustain".
This is very much the first step in a gradual and phased approach to reducing the impact coronavirus will have in the UK.
A significant outbreak is on its way but the government and its advisers believe they can limit its impact by taking the right steps at the right time.
We know the first step is to get people with even relatively moderate flu-like symptoms to self-isolate. To date only those who have been to an affected country or who had had close contact with an infected person had been asked to do this.
This will be followed by further advice later this week that is likely to be focused on protecting the most vulnerable groups - the elderly and those with pre-existing health conditions. Reducing social contact will form part of that.
But drastic steps like closing schools and banning public gatherings are not going to happen in the immediate future.
Prof Whitty said that the balance would tip so that more people would suffer from coronavirus rather than regular seasonal flu, or other respiratory infections.
"We are expecting the numbers to increase initially quite slowly but really quite fast after a while and we have to catch it before the upswing begins," he said.
The government's scientific advisory group for emergencies (Sage) is due to meet on Tuesday, followed by another meeting of the emergency committee, Cobra, on Wednesday.
US authorities are planning to fly home Britons who were on board the virus-hit Grand Princess cruise ship on Tuesday, the Foreign Office said.
Passenger Linda Stennett, from Shrewsbury, told BBC Radio Shropshire the Foreign Office had confirmed in an email that they would be sending a plane to repatriate Britons.
"We know when we dock, that the Americans will be getting off first and that is going to take, they reckon, two to three days, and I think we are after that, hopefully."
The decision to delay closing schools and introduce other strict measures to combat coronavirus has been defended by England's deputy chief medical officer.
Dr Jenny Harries said experts are assessing new cases on an hourly basis to achieve a "balanced response".
She told BBC Breakfast new measures could follow as UK cases begin to rise rapidly over the next two weeks.
Dr Harries said the vast majority of those diagnosed with coronavirus in Britain are "pretty well" but that they may "feel a bit rough for a few days".
She added that people with flu-like symptoms will be advised to self-isolate within 10 to 14 days and, at the same time, significant increases in the number of cases are likely to begin.
Dr Harries said cancelling big outdoor events like football matches would not necessarily be a decision supported by science.
"The virus will not survive very long outside," she said. "Many outdoor events, particularly, are relatively safe."
Italy's extended quarantine measures require residents to stay home, seek permission for essential travel, and justify leaving the country.
British Airways has cancelled all of its flights to and from Italy until 4 April, while Ryanair will cancel all its flights to and from Italy from Friday until 8 April.
Easyjet cancelled the majority of its flights to and from the country and Jet2 cancelled its Italian routes until 26 April.
BA said customers due to fly to or from Italy before 4 April can rebook to a later date until the end of May, move their destination to Geneva or Zurich, or receive a full refund.
A Foreign Office spokesman said: "The advice is that anyone who arrives from Italy subsequent to the Italian government decision should now self-isolate for 14 days."
Downing Street said Italians arriving in the UK were being given the same advice as Britons to self-isolate and that the government had facilities available to accommodate them.
Meanwhile airline Norwegian, which operates from several UK airports, said it was cutting 3,000 flights and reducing staff numbers after a fall in demand it attributed to coronavirus.
Media playback is unsupported on your device
The NHS has unveiled a range of measures as part of its response to try to stop fake news being spread about coronavirus on the internet.
Searches for "coronavirus" on Google, Facebook and YouTube will now promote information from the National Health Service or the World Health Organization.
Health Secretary Matt Hancock said the actions meant the public could access accurate health information "which is more crucial than ever as we continue our response to coronavirus".
On Monday, health officials said people who showed "even minor" signs of respiratory tract infections or a fever would - within the next 14 days - be told to self-isolate for a week in an effort to tackle the outbreak.
The environment department, Defra, said by allowing night-time deliveries - currently restricted to avoid disturbing locals - stock would be able to move more quickly from warehouses to shelves.
Media playback is unsupported on your device
Meanwhile, US authorities are expected to fly home Britons who were on board the virus-hit Grand Princess cruise ship later, according to the Foreign Office.
However, one of the Britons on board, Jackie Bissell, told BBC Radio 4's Today programme she had yet to hear from the ship's captain about her departure.
"They haven't said anything about when we can go," she said. "It's very unnerving to be left out here when we don't know what's going to happen."
Elsewhere, crowds exceeding 60,000 are expected on all four days of horse racing's Cheltenham Festival, which starts on Tuesday afternoon.
It comes after Culture Secretary Oliver Dowden said there was no reason to cancel such events due to coronavirus, although many other sporting fixtures, including the Six Nations and Formula One, have been affected.
What are your experiences relating to the coronavirus outbreak? Share your experiences by emailing haveyoursay@bbc.co.uk.
Please include a contact number if you are willing to speak to a BBC journalist. You can also contact us in the following ways:
