U.S. House Speaker McCarthy arrives for a Republican conference meeting at the U.S. Capitol in Washington
U.S. House Speaker Kevin McCarthy (R-CA) arrives for a Republican conference meeting at the U.S. Capitol in Washington, U.S. January 10, 2023. Reuters

Republicans controlling the U.S. House of Representatives plan to launch an investigation into what they term President Joe Biden's weaponization of the federal government, but Democrats brand it a partisan fishing expedition.

In a vote set for Tuesday, Republicans vow to use their new majority against the Justice Department, FBI and other federal agencies investigating Republican former president Donald Trump and his supporters who on Jan. 6, 2021, stormed the Capitol.

Republicans for months have accused the Biden administration of "weaponization" of the FBI in connection with Trump.

Dubbed the "Select Subcommittee on the Weaponization of the Federal Government," the body is set to launch a wide-ranging investigation of Democrat Biden's administration.

"We will hold the swamp accountable, from the withdrawal of Afghanistan, to the origins of COVID and to the weaponization of the FBI," newly elected House Speaker Kevin McCarthy said on Saturday.

Among the federal agencies targeted are those looking into Trump's attempt to overturn his 2020 defeat and alleged mishandling of classified documents. Trump has dismissed these probes as "witch hunts."

Republican Representative Elise Stefanik, days after the August search of Trump's Mar-a-Lago resort for classified material, promised to launch a probe of "Joe Biden and his administration's weaponization of the Department of Justice and FBI ... The FBI raid of President Trump is a complete abuse and overreach of its authority."

Democrats have raised concerns about a provision that authorizes the committee to probe "ongoing criminal investigations," which are generally outside the purview of congressional oversight.

"This is a violation of separation of powers, and it's also very dangerous," said Jerrold Nadler, the top Democrat on the Judiciary Committee.

On Monday the White House said that lawyers for Biden found classified documents at a Washington think tank affiliated with the president.

Some Republicans compared that discovery to the criminal investigation into Trump's removal of classified documents from the White House, though smaller numbers of papers are involved and Biden's team said it turned them over upon discovery, while Trump resisted calls to return the paperwork and now faces an investigation into whether he obstructed justice.

Legal experts said federal law enforcement agencies would almost certainly reject any attempt by a congressional committee to obtain documents related to ongoing investigations.

Scott Perry, a Republican Judiciary Committee member whose phone was seized as part of the federal probe into efforts to overturn the 2020 election, is among those who might seek a subcommittee seat. That would create a situation where he could seek to oversee a federal investigation into himself.

Republican Representative Brian Fitzpatrick, a former FBI agent, told Reuters he supported the creation of the subcommittee.

But, he added, handing over information on an active investigation was "inconsistent with federal law."

"I'm going to keep an eye on this," he said.