Business Secretary Alok Sharma has been tested for coronavirus and is returning home to self-isolate after becoming visibly unwell in the House of Commons chamber.
The Tory Cabinet minister's spokesperson said tonight he began to feel unwell in the House of Commons chamber "when in the chamber delivering the second reading of the Corporate Governance and Insolvency Bill.
"In line with guidance he has been tested for coronavirus and is returning home to self-isolate," she added.
Sharma was understood to be travelling home to self-isolate after he struggled during the speech at the despatch box today.
The development came a day after MPs approved the Government's plan to end virtual voting in the Commons.
During the debate, he was seen wiping his face with a handkerchief several times and appeared to struggle.
His opposite number in Labour's shadow cabinet, Ed Miliband, passed him a glass of water at one point, as did a Government whip.
Labour shadow minister Toby Perkins had raised concerns over Mr Sharma's appearance in the Commons earlier in the day.
"This is not ok. If he has symptoms that could be Covid-19, it's not up to him to soldier on, he is jeopardising the health of everyone who he comes across and everyone else who touches that despatch box and every door handle he touches etc," Mr Perkins tweeted.
"Maybe he's had a test and knows it's not that, but if so he should confirm that to people watching, otherwise the message again goes out that what the government says and means about what to do if you have symptoms are two different things."
If Mr Sharma has contracted coronavirus in Westminster, it would be a sad vindication of the fury felt by many members of parliament at being forced back to the Houses of Commons in person amid the coronavirus pandemic.
MPs tonight reacted with anger at the news tonight.
MP for Liverpool Walton and shadow financial secretary Dan Carden said: "Rees-Mogg’s insistence on physical voting in parliament puts lives at risk and will spread the virus.
"It cannot be allowed to continue."
MP for Oxford West and Abingdon Layla Moran tweeted: "Get well soon Alok Sharma. I really hope it is not Covid-19.
"MPs and staff will have been put at risk by the Government decision to not keep virtual Parliament.
"And in turn constituents, should he or anyone else, test positive. Bring back virtual proceedings now!"
Labour MP for Newcastle North Catherine McKinnell wrote: "He really didn’t look well, and I hope he’s OK.
"He should not have been in the commons today. In fact, most of us shouldn’t have been.
"The Govt is advising everyone else to avoid public transport and work from home if poss to avoid spreading Covid, but made us all do the opposite."
MP for Bermondsey and Old Southwark Neil Coyle wrote that Sharma was "in that irresponsible and unnecessary queue yesterday.
"Rees-Mogg took a huge and completely avoidable risk and it has backfired badly. Johnson must not take the same approach with whole country."
SNP MP for for Livingston Hannah Bardell said: "This is very worrying. Hope Alok is better soon. Meantime, Jacob Rees Mogg needs to clarity his comments as he said even if members have Covid they can still attend Parliament.
"That is just utter madness."
The Tory plan was approved last night by 261 to 163,after a "farcical and discriminatory" socially-distanced vote - that forced MPs to queue for more than half a kilometre through Parliament.
In bizarre scenes, a snaking line of MPs passed out of the Commons chamber, looped round and round 14th Century Westminster Hall, out into a yard guarded by armed police, down the length of a Victorian-era colonnade, under a main road, back up into a new-build office block and round a corner.
As MPs compared the farce to Alton Towers, Plaid Cymru's Liz Savile Roberts declared it "the world’s worst fairground attraction queue." Labour branded the vote "farcical and discriminatory".
Yet Commons leader Jacob Rees-Mogg claimed "it is important for votes to be physical" - and refused to back down from the barmy new scheme.
Labour's Charlotte Nichols posted a photo of a clogged bottleneck in a Parliamentary underpass. She tweeted: "Social distancing for the vote going spectacularly badly, what a joke."
MP Barbara Keeley added on Monday: "In forcing the return of Parliament, Boris Johnson risks sending a dangerous message to bad employers.
"The Speaker has said that MPs will be unable to vote safely - the current plan for the return is unworkable."
Senior Conservatives, opposition groups and the equalities watchdog raised concerns that the move would prevent many MPs, particularly the elderly and vulnerable ones who are shielding, from being able to vote.
Boris Johnson today dismissed complaints over the system, saying: "I do not think it's unreasonable that we should ask parliamentarians to come back to this place and do their job for the people of this country."
But Labour leader Sir Keir Starmer said the scenes were "shameful" and pushed the Prime Minister to end the "completely unnecessary and unacceptable" process.