Nadine Dorries is now in self-isolation.
London CNN  — 

UK Prime Minister Boris Johnson will not be tested for coronavirus, despite one of his ministers testing positive for coronavirus, raising fears about the potential spread of the disease in Westminster.

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.”

Boris Johnson and Nadine Dorries at an event this year. The pair were both present at a reception in Downing Street last week.

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.