Business Secretary Alok Sharma might have been suffering from “severe hay fever” rather than coronavirus after becoming visibly unwell in the House of Commons chamber, according to a Cabinet colleague.

Mr Sharma is self-isolating after he struggled during a speech at the despatch box during the second reading of the Corporate Insolvency and Governance Bill on Wednesday.

He was also reportedly in Downing Street before his appearance on the green benches.

The Business Secretary has been tested for Covid-19 but Northern Ireland Secretary Brandon Lewis said it would be “premature” to suggest Mr Sharma had the virus.

Speaking to BBC Radio 4’s Today programme, Mr Lewis said: “I don’t want to be premature because Alok, who I wish well and hope he recovers quickly, may well have had severe hay fever, we’re not sure yet.

“He has had a test, he is self-isolating as you say, to take the correct precaution.”

The potential case of Covid-19 in the chamber came a day after MPs approved the Government’s plan to end virtual voting in the Commons, prompting renewed calls for the system to return.

MPs are due to debate a motion laid by Commons Leader Jacob Rees-Mogg on Thursday to allow those who are shielding and those aged over 70 to vote by proxy, in a move Labour dubbed a “U-turn” and described as “chaotic”.

It comes after senior Conservatives, opposition groups and the equalities watchdog raised concerns the decision to end digital voting would prevent many representatives, particularly the elderly and vulnerable ones who are shielding, from being able to vote.

Alok’s situation highlights, if he has got coronavirus, why it is so important that if you are in a work environment, you have got to follow the guidelines

But Mr Lewis denied that Mr Sharma’s case supported the argument for virtual voting in the Commons to be resumed.

He told the BBC: “It is important for parliamentarians to be able to properly scrutinise legislation, not just for Covid but for the wider legislative agenda we have to continue with for people across the country, but to do so within proper guidelines.

“That’s what the House authorities have set up, that’s what’s been working over the last few days and that’s a very good thing.

“It highlights Alok’s situation, if he has got coronavirus, why it is so important that if you are in a work environment, you have got to follow the guidelines.”

During the debate on Wednesday, Mr Sharma was seen wiping his face with a handkerchief several times and his opposite number in Labour’s shadow cabinet, Ed Miliband, passed him a glass of water at one point.

A House of Commons spokeswoman said “additional cleaning” had taken place following the potential case of Covid-19, along with the usual regular wiping down of the despatch box.

Labour shadow minister Toby Perkins had raised concerns over Mr Sharma’s appearance in the Commons earlier in the day, and later doubled down on his criticism after learning of the test.

“This is ridiculous. It was clear that Alok Sharma looked unwell,” he said.

“If there are now fears that he may have Covid-19 and he hadn’t already tested negative, it was the height of irresponsibility for him to be in Parliament sniffling, sweating and snorting from the despatch box.”

The size of the chamber has made it difficult for some MPs to keep their distance as they try to swap seats or move around.

Chaotic scenes unfolded this week when MPs had to form a long queue snaking through Parliament so they could maintain social distancing while voting on the motion to return to physical voting.

Boris Johnson on Wednesday dismissed complaints over the system but Labour leader Sir Keir Starmer said the scenes were “shameful” and pushed for an end to what he called a “completely unnecessary and unacceptable” process.