(Dec 14): Republicans in the US House voted on Wednesday to formally authorise an impeachment inquiry into President Joe Biden, escalating a probe that has been underway for several months.

The 221 to 212 party-line vote sets up a high-profile clash between Congress and the White House as the 2024 election approaches. Republican presidential front runner Donald Trump has urged GOP lawmakers to step up the impeachment inquiry against Biden.

The investigation has focused on Biden family finances and business dealings of the president’s son, Hunter, and other relatives. Biden immediately denounced the inquiry as a “baseless” attack.

“Instead of doing their job on the urgent work that needs to be done, they are choosing to waste time on this baseless political stunt that even Republicans in Congress admit is not supported by facts,” Biden said of Republicans.

The resolution establishes the investigation’s procedures and powers, but doesn’t set a deadline or lay out any specific impeachable offences.

“It’s time to get the American people answers,” said House Speaker Mike Johnson, who argued the formal approval will give congressional committees investigating Biden and his family greater legal authority to enforce subpoenas.

The White House and many congressional Democrats say the inquiry is merely an effort to distract attention from Trump’s criminal trials.

“There is no evidence that President Joe Biden has engaged in wrongdoing,” House Democratic Leader Hakeem Jeffries said. “But the puppetmaster-in-chief, Donald Trump, has directed the sycophants to target Joe Biden as part of an effort to undermine President Biden’s re-election.”

The vote came just hours after the president’s son, Hunter, challenged House Republicans to allow him to testify publicly on his business dealings, but refused to comply with investigators’ subpoena for a scheduled closed-door deposition.

House Judiciary Chairman Jim Jordan said he’s moving towards contempt of Congress proceedings for the president’s son.

Three US presidents have been impeached by the House. Biden’s predecessor, Trump, was impeached twice, but not convicted by the Senate.

The vote on the impeachment inquiry could ultimately prove problematic for 18 Republicans who represent districts Biden won in 2020. Despite low overall approval ratings, Biden remains popular in some of those areas.

Several of the swing-district Republicans, such as Representative Don Bacon of Nebraska, said they voted to back the inquiry, but may not necessarily vote to impeach Biden.

After the vote, New York Republican Marc Molinaro, whose district Biden carried in 2020, said he was concerned about improprieties related at least to Biden’s family.

House panels have been investigating the president and his family since earlier this year without formal authorisation. Public impeachment hearings could begin by February, Jordan has said.