WASHINGTON (Reuters) - Two Republican lawmakers, and no Democrats, are expected to attend a meeting scheduled for Thursday to review classified information relating to U.S. President Donald Trump’s suggestion the FBI might have used an informant to gather information on his 2016 election campaign, the White House said on Tuesday.

Trump’s closest conservative allies in Congress have been clamoring for access to the classified documents. The lawmakers have accused the FBI and Department of Justice of political bias against Trump in favor of Democratic former Secretary of State Hillary Clinton during his successful presidential campaign.

The meeting attendees will be Representatives Devin Nunes, chairman of the House of Representatives Intelligence Committee, and Trey Gowdy, chairman of the House Oversight Committee, White House spokesman Sarah Sanders told the daily news briefing.

FBI Director Christopher Wray, Director of National Intelligence Dan Coats and Acting Principal Associate Deputy Attorney General Ed O’Callaghan are also expected to attend, she said.

Earlier on Tuesday, a group of Republican lawmakers called for the appointment of a second special counsel to investigate the probe into Trump’s campaign, Russia and the 2016 U.S. election, as Trump ramped up his own criticism of the Department of Justice.

At least 18 Republican lawmakers signed onto a resolution calling on U.S. Attorney General Jeff Sessions to appoint a special counsel to investigate the department and the FBI, accusing them of misconduct as Trump campaigned two years ago against Democrat Hillary Clinton.

A spokeswoman for the Department of Justice declined comment.

Slideshow ( 3 images )

Conservatives have been criticizing the department, the FBI and Special Counsel Robert Mueller’s probe of Russian interference in the election for months. Their rhetoric intensified after Trump suggested on Friday that the FBI might have planted or recruited an informant in his presidential campaign for political purposes.

Moscow denies election meddling and Trump denies any collusion between Russian officials and his campaign, calling investigations a political witch hunt.

On Monday, the Justice Department agreed to investigate “any irregularities” in FBI tactics related to Trump’s campaign. The agreement was made during a meeting between Trump, U.S. Deputy Attorney General Rod Rosenstein and Wray.

“It is time for transparency and it is time to allow the American people to know the truth,” Representative Mark Meadows, the Republican who leads the conservative Freedom Caucus, told a news conference announcing the resolution.

Representative Lee Zeldin, who led the push for the resolution, said it would be introduced later on Tuesday.

Zeldin, Meadows and about a dozen other Republicans in the House of Representatives insisted at a news conference announcing the resolution that Trump had not requested a new counsel.

They also called for access, for Democrats as well as Republicans, to all documents related to the case.

There was no immediate response from House leadership aides on whether the measure might come up for a vote. House Speaker Paul Ryan has said repeatedly, however, that he believed Mueller should be allowed to continue his work.