The speaker of the US House of Representatives has unveiled legislation that would allow Congress to intervene to remove Donald Trump as president, insisting it is not about him but inspired by a need for greater congressional oversight of his White House.

Nancy Pelosi has been raising questions about Mr Trump’s mental fitness since his Covid-19 diagnosis and demanding more transparency about his health.

Under the 25th Amendment to the Constitution, the bill would set up a commission to assess the president’s ability to lead the country and ensure continuity of government. It comes a year after Ms Pelosi’s House launched impeachment proceedings against him.

“This is not about President Donald Trump — he will face the judgment of the voters,” Ms Pelosi said at a press conference at the Capitol.

Weeks before the November 3 election, with no hopes of the bill becoming law, the rollout was quickly dismissed as a stunt by Mr Trump’s team and top allies.

“It’s an absurd proposal,” said White House press secretary Kayleigh McEnany.

“Absolutely absurd,” said Senate majority leader Mitch McConnell.

The president’s opponents have discussed invoking the 25th Amendment for some time, but are raising it now, close to Election Day, as the campaigns are fast turning into a referendum on Mr Trump’s handling of the coronavirus pandemic.

Ms Pelosi said he needs to disclose more about his health and when he first contracted Covid-19 as others in the White House have become infected.

More than 210,000 Americans have died and millions more have tested positive for the virus, which shows no signs of abating heading into what public health experts warn will be a difficult flu season and winter.

The legislation that would create a commission was passed by Congress and ratified in 1967 as a way to ensure a continuity of power in the aftermath of John F Kennedy’s assassination.

It says the vice president and a majority of principal officers of the executive departments “or of such other body as Congress” may by law provide a declaration to Congress that the president “is unable to discharge the powers and duties of his office”. At that point, the vice president would assume the powers of acting president.

“Let Congress exert the power the Constitution gave us,” Ms Pelosi said on Friday standing before a poster of the amendment.

She was joined by Democratic representative Jamie Raskin, a constitutional scholar who has proposed similar bills in the past.

“In times of chaos we must hold fast to our Constitution,” he said Friday.

Mr Raskin said the commission would be launched “only for the most extreme situations” but, as Congress showed by impeaching — and acquitting – the president over the past year, the legislative branch is determined to exert itself at times as a check on the executive branch.

“Congress has a role to play,” Mr Raskin said.

Mr Trump says he “feels great” after being admitted to hospital and is back at work in the White House, but his doctors have given mixed signals about his diagnosis and treatment. He plans to resume campaigning soon.

Congress is not in legislative session, so any serious consideration of the measure, let alone votes in the House or Senate, is unlikely, but the bill serves as a political tool to stoke questions about Mr Trump’s health as his own White House is hit by an outbreak infecting senior aides, staff and visitors, including senators.

Mr McConnell admitted on Thursday that he had stopped going to the White House two months ago because he disagreed with its coronavirus protocols. His last visit was on August 6.

“My impression was their approach to how to handle this was different from mine and what I insisted we do in the Senate, which is to wear a mask and practice social distancing,” he said.