Attorney General William Barr said Wednesday he believes the FBI spied on the Trump campaign.

The remarks touched off a partisan debate over the use of the term “spy.”

The FBI relied on at least two confidential informants, Christopher Steele and Stefan Halper, in the investigation of the Trump campaign.

Attorney General William Barr’s Senate testimony Wednesday has revived a partisan debate over “Spygate,” the term President Donald Trump coined to describe revelations that the FBI used informants in an investigation during the 2016 presidential campaign.

Barr said during an appearance before the Senate Appropriations Committee that he believed “spying did occur” against the Trump campaign.

When pressed by senators surprised at the remarks, Barr stood by his initial statement, while clarifying that he considered spying to be “unauthorized surveillance.”

“I believe there is a basis for my concern, but I’m not going to discuss it,” said Barr, who said he plans to investigate whether the alleged spying was “adequately” predicated. (RELATED: ‘SPYGATE’: Trump Rails Against FBI Informant On His Campaign)

Barr’s comments touched off a semantical debate over what constitutes a spy. Critics of the administration have generally dismissed the use of the term, considering it a pejorative meant to imply the FBI engaged in nefarious activity. Trump supporters have largely approved of the language.

“Those hung up on the AG’s use of the word ‘spying’ sound ridiculous. What would you call using human informants to secretly gather information?” North Carolina Rep. Mark Meadows asked on Twitter.

“I call it spying. Because that’s what it is. And bravo to Attorney General Barr for looking in to it,” the Republican tweeted Wednesday.

Those hung up on the AG’s use of the word ‘spying’ sound ridiculous. What would you call using human informants to secretly gather information? I call it spying. Because that’s what it is. And bravo to Attorney General Barr for looking in to it. — Mark Meadows (@RepMarkMeadows) April 10, 2019

The FBI relied on at least two confidential human sources as part of Crossfire Hurricane, the code name for the bureau’s counterintelligence investigation into possible Trump campaign ties to Russia. (RELATED: Barr: ‘I Think Spying Did Occur’ Against Trump Campaign)

Christopher Steele, a former MI6 officer, provided the FBI with information he gathered as part of his infamous dossier. The FBI relied heavily on the dossier, though it was unverified, to obtain surveillance warrants against Carter Page, a Trump adviser who appears throughout the dossier.

The FBI continued surveillance against Page — snooping on his emails and phone calls — through September 2017.

Another FBI informant, Stefan Halper, had contact with Page during the campaign and beyond. Halper, a former professor at the University of Cambridge, also had contact with Trump aides Sam Clovis and George Papadopoulos.

Halper went as far as luring Papadopoulos to London in September 2016 after offering the Trump adviser $3,000 to write a policy paper. Papadopoulos made the all-expenses paid trip to London, where he met with Halper and his purported assistant, a woman named Azra Turk.

Trump coined the term “Spygate” after it was revealed in May 2018 that Halper worked for the FBI.

“SPYGATE could be one of the biggest political scandals in history!” he tweeted on May 23, 2018.

Democrats and liberal journalists bristled at the term, just as they did Barr’s testimony from Wednesday.

“When there is a predicate, a legitimate basis, it’s called ‘investigating’ not ‘spying,'” former Attorney General Eric Holder wrote on Wednesday. “I am confident that the people at DOJ/FBI conducted themselves in an appropriate way. No evidence to suggest otherwise.”

Virginia Sen. Mark Warner, the top Democrat on the Senate Intelligence Committee, called Barr’s remarks “irresponsible.”

Mr. Barr knows how counter-intel investigations work. He knows there was ample evidence of Russian attempts to infiltrate the Trump campaign and that the FBI took lawful action to stop it. Giving a wink and a nod to this long-debunked “spying” conspiracy theory is irresponsible. — Mark Warner (@MarkWarner) April 10, 2019

CNN, which has published numerous stories pushing the collusion conspiracy theory, published a story qualifying Barr’s remarks.

“AG Barr drops ‘spying’ bombshell in hearing, provides no evidence,” the Wednesday headline reads.

Barr did not describe what activities he believe constituted spying on the Trump campaign.

Barr said he plans to form a team at the Justice Department to investigate government agencies’ decision to open counterintelligence investigations against Trump associates. He also revealed on Tuesday that Justice Department Inspector General Michael Horowitz is close to wrapping up an investigation into whether the FBI abused its surveillance power.

Horowitz is scrutinizing how the FBI used Steele and Halper, The New York Times reported. Horowitz’s investigators have asked whether the FBI approved Halper’s outreach to Clovis, according to the newspaper.

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