President Trump asserted Wednesday that the FBI’s use of a confidential source to seek information from his campaign aides was shaping up as a major scandal and that lawmakers would soon realize that “a lot of bad things happened.”

In a series of morning tweets, and later speaking to reporters, Trump assailed what he called “spygate,” claiming that it could become “one of the biggest political scandals in history!”

The comments were Trump’s latest salvo over reports that the FBI used a confidential source in its investigation into Russian interference in the 2016 election.

There is no evidence to suggest that the source was inserted into the Trump campaign, as the president has suggested, but the source did seek out and meet Trump campaign advisers.

On Twitter, Trump suggested that the tables had turned on those investigating his campaign for possible collusion with Russian, writing: “What goes around, comes around!”

The president referred to those investigating him as the “Criminal Deep State,” claiming they had been “caught in a major SPY scandal the likes of which this country may never have seen before!”

As he departed the White House early Wednesday afternoon en route to an event in New York, Trump told reporters: “I hope it’s not true, but it looks like it is.”

The FBI source, a longtime Republican and former University of Cambridge professor Stefan A. Halper, had contact with at least three advisers to Trump during the campaign. Trump and his allies have sought to cast that as inappropriate political spying.

In his tweets, Trump also quoted Andrew Napolitano, a former New Jersey Superior Court judge and frequent Fox News commentator, saying that “it’s clear that they had eyes and ears all over the Trump campaign.” Napolitano appeared on “Fox & Friends” earlier Wednesday morning.

Trump and his aides have derisively used the term “deep state” to refer to long-serving unelected officials who they claim are out to undermine his presidency.

During a television appearance Tuesday, former director of national intelligence James R. Clapper Jr. said that the FBI never spied on the Trump campaign.

“They were not. They were spying — a term I don’t particularly like — on what the Russians were doing,” Clapper said during an appearance on ABCs “The View” to promote a new book.

The FBI, Clapper said, was simply trying to answer the question, “Were the Russians infiltrating, trying to gain access, trying to gain leverage and influence?”

In a later tweet Wednesday morning, Trump took issue with Clapper’s assessment that the then-GOP nominee should have been grateful for the FBI’s surveillance.

“No, James R. Clapper Jr., I am not happy,” Trump wrote. “Spying on a campaign would be illegal, and a scandal to boot!”

The use of the confidential source has been at the fore of Trump and conservative lawmakers’ long-running feud with the Justice Department and special counsel Robert S. Mueller III’s investigation into whether Trump’s campaign coordinated with Russia during the campaign.

On Tuesday, the White House said that two Republican lawmakers will be allowed to review classified information about the FBI source during a meeting Thursday with intelligence officials. The Justice Department had resisted sharing information, saying it jeopardized the source.

Speaking to reporters Wednesday, Trump said he expects “total transparency” from Justice officials.

“What I want is I want total transparency,” he said. “You have to have transparency.”

Trump said that lawmakers will probably be troubled once they see documents regarding the use of the source.

“When they look at the documents, I think people are going to see a lot of bad things happened,” Trump said.

On Wednesday, Senate Minority Leader Charles E. Schumer (D-N.Y.) said he and House Minority Leader Nancy Pelosi (D-Calif.) planned to send a letter to Deputy Attorney General Rod J. Rosenstein and FBI Director Christopher A. Wray requesting that they reconsider meeting with GOP lawmakers. If a meeting takes place, Schumer said, it should include a broader bipartisan group of lawmakers.

“For the President of the United States to pressure the Justice Department to reveal details and documents pertaining to an active investigation of the President’s campaign, for the purpose of denigrating it, is a gross and unprecedented abuse of power,” Schumer said in a tweet.

Former FBI director James B. Comey, whom Trump fired last year, also weighed in on the controversy Wednesday, chastising both the president and GOP lawmakers.

“Facts matter,” Comey wrote on Twitter. “The FBI’s use of Confidential Human Sources (the actual term) is tightly regulated and essential to protecting the country. Attacks on the FBI and lying about its work will do lasting damage to our country. How will Republicans explain this to their grandchildren?”

Speaking to reporters later, Trump sought to discredit Comey, calling him a liar and saying he could be in trouble once a review of the FBI’s handling of the Russia probe is completed by the inspector general of the Justice Department.

“I did a great service to this country by firing James Comey,” Trump said.

Trump also rejected a reporter’s suggestion that he was undercutting the work of the Justice Department.

“No, no. We’re not undercutting,” Trump said. “We’re cleaning everything up. This was a terrible situation. What we’re doing is we’re cleaning everything up. What I’m doing is a service to this country.”

The Russia probe apparently remained on Trump’s mind a couple of hours after his initial tweets Wednesday.

Shortly after 9:30 a.m., he fired off a two-word message in all capital letters: “WITCH HUNT!”