There were no possible incidents of obstructions of justice until after Trump took office.
USA officials have told CNN there was no such source planted inside Trump's campaign to provide information to investigators.
The American professor, who is a Life Fellow of Magdalene College, has not commented on the reports. In response, the Justice Department moved to defuse the confrontation by asking its watchdog to investigate whether there was inappropriate surveillance.
The meeting, which was not on the White House's public schedule, occurred the day after Trump demanded an investigation over a government informant's meeting with several people connected with his campaign in 2016.
Two Republican lawmakers, and no Democrats, are expected to attend a meeting that has been scheduled for Thursday to allow them to review classified information relating to claims the Federal Bureau of Investigation used an informant to gather information on Trump's presidential campaign, the White House said on Tuesday.
Mr. Zeldin, Mr. Meadows and about a dozen other Republicans in the House of Representatives insisted at a news conference announcing the resolution that Mr. Trump had not requested a new counsel. "It would make probably every political event ever look like small potatoes".
On Monday, Trump campaign adviser Michael Caputo told Fox News there might be at least two informants and said that he was also approached.
"If they had spies in my campaign, during my campaign for political purposes, that would be unprecedented in the history of our country", he said.More news: Iran rejects US' threatening remarks against its nuclear programme
There have been whispers and reports for months that the president might fire Rosenstein over his handling of the special counsel-led Russian Federation probe. "That's my guess. We're trying to get clarification from the department", Schiff said. Justice Department officials have been reluctant to turn over the materials, though on Monday, after meeting with Trump at the White House, they reached an agreement to have another gathering where lawmakers could review information. She said no Democrats were invited because they had not requested the information, despite calls from lawmakers for the briefing to be bipartisan.
Rep. Jim Jordan, R-Ohio, speaks next to Rep.
Caputo said he has told the House Intelligence and Senate Intelligence Committees about the offer, as well as the special counsel team led by Robert Mueller. It remains unclear exactly what the lawmakers will be allowed to review or if the Justice Department will be providing any documents to Congress.
"We've been here before", Meadows said.
"If anyone did infiltrate or surveil participants in a presidential campaign for inappropriate purposes, we need to know about it and take appropriate action", said Deputy Attorney General Rod Rosenstein.
Sources have said, however, that Mueller will not accept written answers to questions.
House Speaker Paul D. Ryan (R-Wis.) has also not promised the conservative Republicans pushing for a vote on their resolution that he will give it time on the floor.
FILE - In this Thursday, May 17, 2018, file photo, U.S. President Donald Trump speaks during a meeting in the Cabinet Room of the White House, in Washington. A spokeswoman for Ryan did not immediately respond to a request seeking clarity on Ryan's plans.