President Trump on Sunday said he will officially “demand” that the Department of Justice investigate whether the FBI “infiltrated” his 2016 campaign during the Obama administration.

“I hereby demand, and will do so officially tomorrow, that the Department of Justice look into whether or not the FBI/DOJ infiltrated or surveilled the Trump Campaign for Political Purposes – and if any such demands or requests were made by people within the Obama Administration!” Trump wrote on Twitter.

The posting comes amid a barrage of eight tweets Trump unleashed Sunday about special counsel Robert Mueller’s Russia probe, calling it “the world’s most expensive Witch Hunt,” denying collusion and calling for Hillary Clinton’s campaign to be investigated for her use of a private email server when she was President Barack Obama’s secretary of state.

The “demand” tweet was in response to a New York Times report Friday that an FBI informant met with a number of Trump campaign associates in the summer of 2016.

Rep. Devin Nunes, the GOP chairman of the House Intelligence Committee, has asked the DOJ to turn over documents divulging why the FBI launched an investigation into the Trump campaign. The California lawmaker said if the FBI ran a spy ring inside Trump’s campaign outfit, that “is an absolute red line.”

“There is no possible way that we should be allowing, even if it was legal, we should never allow this in this country,” Nunes said on Fox’s “Sunday Morning Futures.” “Congress should not allow for anything like this to ever occur again to any political campaign, if it in fact happened.”

Rep. Adam Schiff, the ranking Democrat on Nunes’ panel, said Trump’s actions are an “abuse of power.”

“Trump’s claim of an embedded ‘spy’ is nonsense. His ‘demand’ DOJ investigate something they know to be untrue is an abuse of power, and an effort to distract from his growing legal problems,” Schiff said in a tweet. “Never mind that DOJ has warned that lives and alliances are at risk. He doesn’t care.”

Rudy Giuliani, Trump’s lawyer, said the president would be “walking into a trap” if he agreed to be interviewed by Mueller’s team without clarification on the role of the informant.

“What we intend to do is premise it on, ‘If you want an interview, we need an answer to this,’” Giuliani told the Wall Street Journal in an interview published Sunday.

Trump’s legal crew would need to know whether the FBI informant compiled “incriminating information” about the aides.

A spokeswoman said the DOJ has asked the agency’s inspector general to expand the probe launched in March.

“As always, the Inspector General will consult with the appropriate U.S. Attorney if there is any evidence of potential criminal conduct,” Sarah Isqur Flores said.

Deputy Attorney General Rod Rosenstein said in a statement: “If anyone did infiltrate or surveil participants in a presidential campaign for inappropriate purposes, we need to know about it and take appropriate action.”

The informant, identified by numerous news outlets as Cambridge professor Stefan Halper, met with campaign aides Carter Page, Sam Clovis and George Papadopoulos in the summer of 2016. Page and Clovis testified to grand juries, and Papadopolous pleaded guilty in October 2017 to lying to the FBI about his contacts with Kremlin-linked Russians and is cooperating in the Mueller probe.

The FBI had been monitoring Page since 2013, when they learned Russian agents were trying to recruit him.

As the investigation reached the one year mark last week, the president, his legal team and some Republican allies have stepped up their attacks on the former FBI director.