WASHINGTON — The leading members of the House Intelligence Committee haven’t seen and don’t expect to see any evidence backing up President Trump’s allegations that Trump Tower was wiretapped during last year’s presidential campaign.

With the committee scheduled to take its first public testimony Monday in its investigation of Russian meddling in the election, the committee’s Republican chairman and its senior Democrat voiced agreement Wednesday that no evidence is likely to emerge of Trump’s allegations that President Barack Obama had ordered the tapping of Trump’s phones.

Meanwhile, in the Senate, Lindsey Graham, R-S.C., said he’d asked the FBI to confirm or deny that there’s an active investigation into allegations that the Trump campaign worked with Russia and to detail if any U.S. court had been asked to issue a warrant to surveil communications at Trump Tower. Graham said the FBI told him those questions would be answered in a closed hearing.

Whether Trump was monitored has been an issue since March 4 when the president, in a series of tweets, accused Obama of wiretapping him in the waning days of the campaign. The House committee agreed to add the allegations to its investigation of Russian meddling in last year’s election and asked the Justice Department to provide any evidence bolstering Trump’s claim by March 13. That deadline was later moved to next Monday.

“We don’t expect to find that there was any substance to the allegations,” said Rep. Adam Schiff, a Californian who is the senior Democrat on the House intelligence panel. Later, Rep. Devin Nunes, a California Republican and the committee’s chairman, shook his head and laughed when asked about the president’s tweeted accusations.

“I think the president tweeting is a good thing,” Nunes said. Then he added: “There’s a fine line between having too many people monitoring what he’s saying, and no one monitor what he’s saying. … It would be helpful if they could be a little more focused.

“I don’t think there was an actual tap of Trump Tower,” said Nunes, adding that if Trump’s Twitter claim is to be taken literally, “then clearly the president is wrong.”

The bipartisan agreement that no evidence is likely to emerge backing the president’s allegations would seem to mark an end to two weeks of contentious claims that put Trump’s credibility on the line.

“There are, from a national security perspective, great concerns that the president is willing to say things like that without any basis. The country needs to be able to rely on him,” Schiff said in comments notable largely because they went unchallenged by Nunes, who played a key role in the Trump transition.

Still, White House press secretary Sean Spicer defended Trump’s tweets. “The president feels very comfortable there is information out there on surveillance,” Spicer said, saying the president’s concerns were not limited to actual wiretaps, but to the monitoring of communications in general.

Nunes and Schiff also released a letter showing that they intend to investigate a series of leaks that, among other things, revealed that Trump’s former national security adviser, Michael Flynn, had been monitored speaking with Russian Ambassador Sergey Kislyak and that the FBI had warned the White House that a transcript of that call contradicted Flynn’s version of what took place.

In the letter to FBI director James Comey, National Security Agency director Adm. Mike Rogers and CIA director Mike Pompeo, Nunes and Schiff asked for the names of all Americans who, like Flynn, had been incidentally recorded between last June and January. Flynn’s conversations with Kislyak took place at the end of December. The letter notes that the release of names and information regarding Americans recorded while talking to subjects of wiretaps, called incidental capture, needed to be investigated and stopped.

Flynn resigned in February at Trump’s request after only 24 days in office, hours after The Washington Post had revealed the FBI’s warning to the White House. The resignation came three weeks after the Justice Department told the White House that the captured phone call suggested that Flynn had lied to Vice President Mike Pence about the content of those conversations.

The House committee will take testimony in open session from Comey and Rogers on Monday, the first public hearing in its investigation of Russian election meddling. A second hearing will be on March 28, where testimony will be taken from former CIA director John Brennan, former director of national intelligence James Clapper and Sally Yates, who as acting attorney general told the White House on Jan. 23 that Flynn had been overheard talking to Kislyak on Dec. 29.

Graham’s hearing Wednesday, of a subcommittee on crime and terrorism, focused on Russian meddling in other nations’ elections and featured testimony from a former president of Estonia, among others, who concluded that without a strong U.S. response, the Russians will move more forcefully to disrupt future U.S. elections.

“I think the Russians are coming for all of us,” Graham said.