Health minister and Conservative MP Nadine Dorries has been diagnosed with coronavirus.
Ms Dorries said she has been self-isolating at home. Labour MP Rachael Maskell said she has since been told to do the same as she had met Ms Dorries.
The Department of Health said Ms Dorries first showed symptoms on Thursday – the same day she attended an event hosted by the prime minister.
Six people with the virus have died in the UK, which has a total of 382 cases.