A video produced to kickoff Sen. Rand Paul’s presidential campaign may have run afoul of Senate rules designed to separate official government resources from electioneering.

The April 5 video, released two days before Paul announced his presidential bid in Louisville, includes a clip of the Kentucky Republican on the Senate floor during the nearly 13-hour filibuster in 2013 in which he temporarily blocked the John Brennan nomination for CIA director over criticism of drone warfare. Using the footage, contained in a Fox News package on the filibuster, appears to violate Senate guidelines on the use of video footage of Senate, an issue first flagged by a Democratic operative speaking to TIME.

“The use of any tape duplication of radio or television coverage of the proceedings of the Senate for political campaign purposes is strictly prohibited,” the Senate Manual states.

Jason Abel, an attorney for Steptoe & Johnson and former chief counsel to Democratic Senator Chuck Schumer on the Rules & Administration Committee, told TIME that the video contradicts a rule that prohibits the use of television coverage on the Senate floor for political campaign purposes.

“As a general matter, floor proceedings should not be used for any campaign purposes, even if it is footage from a news outlet,” he said. “The thinking behind this is any official’s actions or official resources should not be used for campaign purposes. The rules look at floor proceedings as official actions.”

A spokesman for the Democratic minority on the Rules committee told TIME that “after reviewing the information, it appears to be a violation of the Senate rules.”

Republicans and Paul’s campaign argue that the use of the video is acceptable, but did not explain their rationale.

“Use of footage produced by a news organization does not necessarily violate the rule,” says Amber Marchand, a spokeswoman for Senate Rules Chairman Roy Blunt. “We defer to the Chairman,” says Sergio Gor, a spokesman for the Paul campaign.

Abel added that violations of this rule are generally handled by the Rules committee, not the Ethics committee, but Democrats in the minority would not be able to take action unilaterally. Typically, the remedy is asking the Senator to pull the video or to remove the footage from it.

The issue has raised its head before. In 2004, an ad for President George W. Bush’s re-election campaign raised similar questions after using brief clips from the Senate floor to criticize then-Massachusetts Sen. John Kerry’s voting record on military issues. The Bush campaign denied any wrongdoing and the ad continued to run. In 2014, then-Louisiana Sen. Mary Landrieu re-enacted a contentious Senate hearing for an ad to avoid running afoul of the rule.

The Paul video announced that on April 7, when Paul officially launched his White House run, a “different kind of Republican will take on Washington.”

With reporting by Michael Scherer/Washington, D.C.

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