The House of Commons voting procedure may have put MPs at risk by exposing them to droplets that could potentially have been left in the air, experts have said.

The comments come as MPs were forced to join a queue that snaked for hundreds of metres to decide their voting method during the coronavirus pandemic.

They were repeatedly reminded to observe social distancing measures by keeping two metres apart as they queued before walking through the Commons chamber and announcing their vote one after another.

But some experts have said this would not necessarily have been enough to mitigate any potential risk of infection spreading, especially given that they were indoors.

Linda Bauld, professor of public health at the University of Edinburgh, said it was “insane” to make MPs return to the Commons to vote.

She told the PA news agency: “I thought that was a really insane idea to require people to go back into Westminster, in terms of infection controls.”

Prof Bauld added that the science was evolving, but “it wouldn’t be outside the realm of possibility that immediately occupying the same space as somebody who’s been speaking could be a risk”.

She explained: “That wouldn’t necessarily be about the fact that they have to be coughing or sneezing.

“I think these small droplets that we emit when we breathe normally are still a risk and that’s why close contact is a risk.

“So immediately occupying the same space as somebody is probably not a great idea.

“I think it could definitely put them at risk. I think the bigger point is really not setting a good example but it is potentially pretty risky.”

Lawrence Young, professor of molecular oncology at Warwick Medical School, University of Warwick, said the Commons voting process was “disturbing”.

He told PA: “Keeping socially distanced is important as is recognising that there is an increased risk of infection in an indoors environment where there is no breeze or air movement.

“Respiratory droplets can spread the virus (even from asymptomatic individuals) and recent work suggests that simply breathing or talking could release tiny particles which can stay suspended in the air in a fine mist produced when infected people exhale.”

Keeping socially distanced is important as is recognising that there is an increased risk of infection in an indoors environment where there is no breeze or air movement

Last month a study from researchers at the National Institute of Diabetes and Digestive and Kidney Diseases and the University of Pennsylvania, found that tiny airborne droplets produced through speech can linger in the air for longer than 10 minutes – and may be potentially significant in the spread of coronavirus.

While the research did not involve the coronavirus or any other virus, it looked at how people generate respiratory droplets when they speak.

According to the researchers, these droplets still could potentially contain enough virus particles to represent an infectious dose.

As well as the risk posed by the queuing and stepping forward, some MPs were seen to touch the despatch box as they voted.

Prof Young said: “As for touching contaminated surfaces, we think that this is a potential source of infection – hence frequent hand washing and wearing gloves.”

But Prof Bauld suggested the box should have been cleaned after someone touched it, saying “If it was a university environment, we’d be cleaning the podium before the next lecturer came to do their lecture.”

She further said it was important for leadership to lead by example, adding: “This is the thing we saw with Dominic Cummings.

“If you’re going to trust the Government and leadership, you need to be confident that they are leading by example.

“And if they are asking the higher education system, employers etc to keep their staff working from home where possible and switch to electronic decision making, electronic communication – which is certainly you know viable, but does require investment, and also breaking from tradition – it is important that they do lead by example.”

Michael Tildesley, an associate professor at Warwick who specialises in infectious disease control, said that while there was a risk of the infection spreading, that had to be weighed up against trying to resume normal activities and getting the economy running again.

He added: “Theoretically, if they were maintaining social distancing and keeping the gap between individuals, it should be no less safe than being in a queue.

“If they’ve washed their hands before they’ve come into the chamber and they’re not coughing and sneezing, then hopefully there should be minimal risk of transmission.”