U.S. lawmakers on Sunday called on President Donald Trump to turn over any tapes of conversations with fired FBI chief James Comey, potentially setting up a showdown with the White House as Democrats considered a boycott of the vote on Comeys replacement.

In a highly unusual move, Trump last week appeared to suggest on Twitter that he might have tapes of conversations with Comey and warned the former director of the Federal Bureau of Investigation against talking to the media. Trump and a White House spokesman declined to confirm or deny whether such tapes exist.

Republican Senator Lindsey Graham of South Carolina said the White House must clear the air about whether there are any taped conversations.

You cant be cute about tapes. If there are any tapes of this conversation, they need to be turned over, Graham told NBCs Meet the Press program.

Trump sparked a political firestorm when he abruptly fired Comey last week. The FBI has been investigating alleged Russian meddling in the U.S. election and possible ties between Moscow and the Trump campaign.

Democrats have accused Trump of attempting to thwart the FBIs probe and have called for some type of independent inquiry into the matter.

Trump has said he removed Comey because he was not doing a good job and that Comey had lost the support of FBI employees.

Trump tweeted on Friday that James Comey better hope that there are no tapes of our conversations before he starts leaking to the press!

If there are recordings, Republican Senator Mike Lee of Utah told the Fox News Sunday program it was inevitable that they would be subpoenaed and the White House would have to release them.

Lee, who was on Trumps list of potential replacements for Supreme Court Justice Antonin Scalia, also said recording conversations in the White House is not necessarily the best idea.