The US House of Representatives has voted to formally open an impeachment inquiry into president Joe Biden, moving forward a process that has been promised by Republican leaders since they regained control of the lower chamber in midterm elections in 2022.

Although no evidence has been produced, Republicans have accused Biden and his family of personally profiting from his position while vice-president under Barack Obama.

The president responded to the vote by saying his opponents were attacking him “with lies”, but Wednesday’s events set in train a process which could lead to impeachment – the ultimate penalty for a president.

Why has the vote happened now?

House Republicans informally began the probe into Biden three months ago, but Wednesday’s vote formalises it. Republicans say that by authorising the inquiry, the White House will be forced to cooperate.

In November a top White House attorney portrayed the investigation as illegitimate because the House had not yet formalised the impeachment inquiry through a vote. The White House has rebuffed efforts to force it to turn over information citing the need for a full House vote.

The inquiry could also vie Republicans a platform to highlight their allegations that the president has behaved corruptly. Biden is preparing for an election rematch with Donald Trump, who was the first president in US history to be impeached twice and is currently preparing for four criminal trials.

Trump has pushed his Republican allies in Congress to move swiftly on impeaching Biden.

Is there evidence that Joe Biden committed wrongdoing?

Republicans have accused the president and his family of profiting from his time as vice-president and have zeroed in on his son, Hunter, who had business ventures in Ukraine and China during that period.

Congressional investigators have obtained nearly 40,000 pages of subpoenaed bank records and dozens of hours of testimony from key witnesses, but while investigations have raised ethical questions, no evidence has emerged that Biden acted corruptly or accepted bribes in his current or previous role.

In July, one of Hunter Biden’s former business associates, Devon Archer, gave sworn testimony to congressional investigators that Hunter had sold his foreign clients “an illusion of access to his father”. Archer recounted how Hunter would put his father on speakerphone to impress clients and business associates, however he also stated that Joe Biden was never directly involved in their financial dealings.

Republicans have also pointed to a couple of falsehoods in Biden’s public statements about his son’s business dealings. For example, during the 2020 presidential campaign, Biden said that his son had never made any money off business transactions in China. That was later contradicted by Hunter Biden himself.

However, at a high-profile impeachment hearing in September, all three Republican expert witnesses who testified conceded they did not have first-hand knowledge of any criminal activity by Biden. Two of those witnesses acknowledged that the information put forward so far by the committee did not amount to corruption.

What happens next?

Authorising the months-long inquiry ensures that the impeachment investigation extends well into 2024 – and could represent a major headache for the president in the midst of an election year.

In the short term, the House’s action gives the three Republican controlled House committees leading the inquiry more power to subpoena documents and testimony – and for judges to enforce those requests.

If the committees decide to move forward with impeachment, the full House of Representatives will vote. If the majority vote yes, Biden will be impeached.

The Senate will then hold a trial and vote on whether to remove the president from office. While three past presidents have been impeached by the House, no president has ever been removed from office.

Will Biden be impeached?

US political history would suggest that things do not bode well for Biden. Of the four presidents who have faced inquiries, three – Andrew Johnson, Bill Clinton and Donald Trump – have ended up being impeached. The fourth – Richard Nixon – only escaped the reprimand by resigning before the vote took place.

However, the Republicans’ thin majority in the House mean that they can only afford to lose a few votes when the situation comes to a head.

Despite the fact that all Republicans in the House voted to formally open the inquiry, some – particularly those from politically divided districts – have been hesitant to back a full impeachment, fearing a significant political cost.

Republican Dusty Johnson said: “If we don’t have the receipts, that should constrain what the House does long-term.”

Another Republican, Ken Buck, said his party was engaging in “retribution impeachments”, while yet another said Biden had “probably not” committed an impeachable offence.

It’s even less certain that the American public would back any attempt to impeach the president.

A poll from CNN in October showed that 57% of Americans thought Biden shouldn’t be impeached. According to the Washington Post, that’s between 10 and 14 points higher than in similar polls taken on attitudes toward Trump’s two impeachments.

Even if the House does vote to impeach Biden, it’s highly unlikely that he would be removed from office.

Sixty senators would have to vote to convict Biden for that to happen, and with Democrats in control of the Senate that outcome would be virtually impossible.

The Associated Press contributed to this report