Kate Osborne has become the second MP to be diagnosed with coronavirus, as a peer became the first in the House of Lords to self-isolate.
Labour MP Ms Osborne tweeted she "will continue to self isolate until I have fought off the illness, but in the mean time I would encourage everyone to band together and support the most vulnerable in our communities".
The Jarrow MP added how her constituents can still contact her on her email address.
The diagnosis announcement was followed by news that Baroness Northover, a Liberal Democrat peer, is self-isolating after developing symptoms last week.
A Liberal Democrat spokesperson said: “In line with advice from Public Health England, Lindsay Northover is self-isolating after experiencing Covid-19symptoms. We are pleased she is recovering well.”
There are now two MPs who have been diagnosed with the virus after health minister Nadine Dorries became the first.
It comes after the UK death toll reached 35, with the number of confirmed positive tests at at least 1,372.
The Prime Minister will chair an emergency meeting of the Cobra committee on Monday afternoon before addressing the first of the daily press conferences being planned to update the public on Covid-19.
As part of the government's response, Health Secretary Matt Hancock said that over-70s could be told to stay home for up to four months within the "coming weeks".
Mr Johnson was expected to discuss the proposal, as well as banning mass gatherings and isolating entire households if one member shows symptoms, during the emergency meeting.
Meanwhile, health minister Edward Argar, who was self-isolating, has returned to work after experiencing no symptoms.
Other plans being considered include handing police powers to detain people with the virus who are not following the advice to protect the wider community by self-isolating.
A number of MPs have entered self-isolation after coming into contact with Ms Dorries or following the official advice.
Cabinet minister Anne-Marie Trevelyan said on Friday that she has tested negative for the virus, but will stay at home for seven days as a precaution.