Republican US House of Representatives Speaker Kevin McCarthy on Tuesday called for an impeachment inquiry into Democratic President Joe Biden, a move certain to further divide lawmakers as they struggle to pass legislation to avoid a government shutdown.

Many in McCarthy’s party were infuriated when the House, then controlled by Democrats, twice impeached Republican president Donald Trump, in 2019 and 2021, though he was acquitted both times in the Senate.

Some lawmakers on the Republican right flank have said they would try to remove McCarthy as the leader of the House if he did not move ahead with an impeachment effort against Biden.

Biden, who defeated Trump in the 2020 election, is seeking re-election next year.

“I am directing our House committees to open a formal impeachment inquiry into President Joe Biden,” McCarthy told reporters. “We will go where the evidence takes us.”

Republicans, who now narrowly control the House, have accused Biden of profiting while he served as vice president from 2009 to 2017 from his son Hunter Biden’s foreign business ventures, though they have not presented substantiation.

McCarthy said lawmakers on several committees will begin gathering evidence of possible financial misconduct.

A former business associate of the younger Biden told a House hearing that Hunter Biden sold the “illusion” of access to power while his father was vice president, according to a transcript released last month.

The White House has said there is no basis for an investigation and Biden has mocked Republicans over a possible impeachment.

Democrats have sought to portray Republican impeachment talk as an effort to distract public attention from the legal woes of Trump, who faces four separate criminal indictments while running for his party’s nomination to face Biden in the 2024 US election.

Trump has pressed Republicans to try to remove Biden from office. Several hard-right Republicans have said they will not vote for must-pass spending bills unless McCarthy greenlights an impeachment inquiry.

The US Constitution empowers Congress to impeach federal officials, including the president, for treason, bribery and “other high crimes and misdemeanours”.

A president can be removed from office if the House approves articles of impeachment by a simple majority and the Senate votes by a two-thirds majority to convict after holding a trial.

Any Biden impeachment effort would be unlikely to succeed. Even if the Republican-controlled House votes to impeach Biden — an uncertain prospect, given the party’s narrow 222-212 vote margin — it would almost certainly fail in the Democratic-controlled Senate.

Trump is the only US president to have been impeached twice. He was acquitted both times after trials in the Senate thanks to votes by his fellow Republicans that prevented the chamber from achieving the two-thirds majority needed for conviction.

In his first impeachment, the House in 2019 charged Trump with abuse of power and obstruction of Congress after he asked Ukraine to investigate Biden and his son on unsubstantiated corruption accusations.

In his second impeachment, the House impeached him in 2021 on a charge of inciting an insurrection following the attack on the US Capitol by his supporters.

The first impeachment sought to remove him from office. The second, with a trial held after he left office, sought to disqualify Trump from ever again holding the presidency.

Trump, as he has done with many investigations into his actions, called both impeachments politically motivated witch hunts.

Biden in July mocked Republican lawmakers threatening to impeach him.

“Republicans may have to find something else to criticise me for now that inflation is coming down. Maybe they’ll decide to impeach me because it’s coming down. I don’t know. I’d love that one,” Biden said at the time.