Senate Majority Leader Mitch McConnell (R-KY) on Wednesday defended President Donald Trump’s decision to fire James Comey as director of the FBI. McConnell also argued against appointing a special prosecutor to investigate Russian meddling in the 2016 election.

The abrupt firing on Tuesday night rocked the political world, with many Democrats, including Senate Minority leader Chuck Schumer (D-NY), saying the move stunk of a cover-up. Comey confirmed under oath on March 20 that he was investigating the Trump campaign for potential collusion with Russia during the 2016 campaign.

However, in the memo cited by Trump as justification for Comey’s firing, newly minted Deputy Attorney General Rod Rosenstein said Comey had bungled another investigation: the probe into Hillary Clinton’s use of a private email server.

McConnell noted on the Senate floor Wednesday that Democrats had been critical of Comey’s handling of the email investigation.

“Last year the current Democratic leader said it appeared to be an appalling act, one that he said goes against the tradition of prosecutors at every level of government,” he said, referring to Schumer’s criticism of Comey’s actions in the days before the presidential election. “And the prior Democratic leader, when asked if James Comey should resign given his conduct of the investigation, he replied ‘Of course. Yes.’”

McConnell also argued that a new investigation of the potential connections between Trump and his affiliates and Russia — Democrats have called for both a special prosecutor and an independent commission on the matter — would only impede the existing investigations.

“Two investigations are currently ongoing,” he said, naming the Senate Intelligence Committee and FBI investigations. “Today we’ll no doubt hear calls for a new investigation, which could only serve to impede the current work being done to not only discover what the Russians may have done, but also to let this body and the national security community develop countermeasures and war fighting doctrine to see that it doesn’t occur again.”

“Partisan calls should not delay the considerable work of chairman Burr and vice chairman Warner,” he said, referring to the chair and vice chair of the Senate Intelligence Committee, respectively. “Too much is at stake.”

After Comey’s firing, Burr said he was “troubled by the timing and reasoning of Director Comey’s termination.”

“It is deeply troubling that the president has fired the FBI director during an active counterintelligence investigation into improper contacts between the Trump campaign and Russia,” Warner said in a statement, which also called the firing “shocking.”

While former Senate Minority Leader Harry Reid (D-NV) supported Comey’s resignation in December, Democrats argued Tuesday that the timing of Comey’s firing was suspect: it occurred months after their heavy criticism of Comey’s handling of the email investigation, but before the Justice Department’s inspector general released a report — announced in January — on the FBI and the Justice Department’s actions during the election.

McConnell also noted Democrats’ support of Rosenstein, whose memo supporting Comey’s firing was published at the end of just his second week in office. McConnell said it was “clear that our Democratic colleagues think of the man who evaluated Mr. Comey’s professional conduct and concluded that the bureau needed a change in leadership.”

“The Democratic leader just a few weeks ago praised Mr. Rosenstein for his independence and said he had developed a reputation for integrity,” he said.