The controversial, classified Republican memo says Deputy Attorney General Rod Rosenstein approved continued surveillance of Trump aide Carter Page last spring, indicating the Justice Department suspected at the time Page could be acting as a Russian agent, according to a new report by the New York Times.

Page, who served as Trump’s foreign policy advisor until September 2016, had come under FBI scrutiny in 2014 for his contact with Russian agents, and he admitted more recently to taking a trip to Russia in 2016 while he worked on Trump’s campaign. Page has not been charged with any wrongdoing.

Republicans have claimed the memo, which was written by Rep. Devin Nunes and has become a hot topic on the right, discredits the investigation into Russian election meddling because, they argue, the warrant for Page was improperly obtained using information from the Russia Dossier. The Republicans have argued that the FBI and Justice Department were required to disclose in the application that the dossier came from intel funded by Democrats. Democrats have argued the Republican depiction of the investigation in misleading and have written their own memo as a response. There has been no public information that has indicated the DOJ or FBI acted improperly while seeking the warrant.

The report in the Times suggests Republicans might now attack Rosenstein’s credibility more directly. Rosenstein, who is tasked with overseeing Mueller’s Russia investigation, has increasingly frustrated Trump in recent weeks to the point that the president has reportedly been making comments about wanting to fire him.

The campaign against the Russia investigation is likely to see tensions grow even more between Rosenstein and Congressional Republicans, as well as between Rosenstein and others in the White House. Trump has indicated he wants the memo to be released, but the DOJ has objected, saying the classified material in the memo needs to be officially reviewed.

According to the Times, House Intelligence Committee Republicans could vote this week to declassify the memo.