(CNN) Senate Democrats are threatening to sue for documents related to Supreme Court nominee Brett Kavanaugh's record, the latest escalation in a partisan battle over the court.

On Thursday, Senate Minority Leader Chuck Schumer said Democrats were prepared to sue if their Freedom of Information Act request for all documents related to Kavanaugh's time in the George W. Bush White House -- both as staff secretary and in the White House counsel's office -- was denied.

"Today we are announcing we stand ready to sue the National Archives for Judge Kavanaugh's full record if necessary," the New York Democrat said.

Republicans have argued that documents related to Kavanaugh's three years as staff secretary are not relevant to his confirmation to the highest court, but Democrats says Republicans' decision to withhold the records constitutes a threat to transparency.

"I think they're feeling under a lot of pressure. I get it. They know they can't stop the confirmation, but they've got to put on a good show, and I assume that's what is going on here," said Sen. John Cornyn, a Texan who's the No. 2 Republican in the Senate as the majority whip.

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