Labour has accused former minister Sir Desmond Swayne of spreading “dangerous misinformation” about coronavirus and has called for the Tories to take action.

Angela Rayner, deputy Labour leader, has written to Conservative Party chairwoman Amanda Milling about alleged remarks made by the veteran politician in which he reportedly said that Covid-19 infection and mortality figures had been “manipulated”.

The Government’s figure for coronavirus deaths passed 100,000 this week, with separate data published by statistics agencies placing the toll at 115,000.

More than 37,000 people are currently in hospital being treated for the virus, according to official data.

In comments reportedly made in November, the lockdown-sceptic Tory MP told the group Save Our Rights UK that the UK was “bouncing round at the typical level of deaths for the time of year”.

According to Sky News, Sir Desmond is alleged to have said: “It seems to be a manageable risk, particularly as figures have been manipulated… We’re told there is a deathly, deadly pandemic proceeding at the moment.

“That is difficult to reconcile with ICUs (intensive care units) actually operating at typical occupation levels for the time of year and us bouncing round at the typical level of deaths for the time of year.”

Sir Desmond has denied that he is opposed to vaccinating people to protect them against the virus. But he has previously labelled lockdowns a “complete failure”.

In her letter, Ms Rayner said the reports were “extremely concerning”.

“During this interview, the MP for New Forest West endorsed conspiracy theories about the veracity of the disease,” she said.

“He also suggested the official figures have been manipulated – a deeply dangerous claim for which there is absolutely no evidence.

“The seriousness of his actions cannot be understated. For a Member of Parliament to appear on this platform and undermine our fight against the pandemic could have truly devastating consequences.

“Following Desmond Swayne’s shocking refusal to apologise for his behaviour, I urge you to make clear what action you will take. It is the duty of all of us to support the national effort to vaccinate Britain.”

Imran Ahmed, chief executive of the Center for Countering Digital Hate (CCDH), which has been investigating online misinformation about coronavirus and vaccines, said Sir Desmond’s words had given “legitimacy to crank anti-vaxxers”.

“This MP’s judgment needs to be seriously questioned when, by virtue of association, he lends legitimacy to crank Anti-Vaxxers and peddlers of falsehoods about Covid,” Mr Ahmed said.

“When we wear a mask or get vaccinated, we don’t just protect ourselves, we also protect those we love, the community we spend time in, and in turn help secure our country against coronavirus.

“While Covid continues to kill, turning science into a political football is a Trumpian act of grotesque irresponsibility.”

Sir Desmond took to Twitter to defend himself, posting: “Sky is wrong. Aside from my question to the PM this afternoon, an examination of my blogs will reveal that I am a most enthusiastic vaccinator.”