The National Archives and Records Administration warned lawmakers Thursday that it won't be able to fulfill a GOP request for documents on Supreme Court nominee Brett Kavanaugh until October, throwing a potential wrench into Republicans' confirmation timeline.

Republicans in the Senate Judiciary Committee have requested documents relating to Kavanaugh's service from 2001 to 2003, when he was a White House lawyer under former President George W. Bush.

Gary Stern, general counsel for the National Archives, sent a letter to the chairman of the committee, Senator Chuck Grassley of Iowa, that said although some records could be produced earlier, a complete review would be completed "by the end of October."

A spokesman for Grassley said the committee will still be able to undertake its review along the same timeline set previously, which puts Kavanaugh on track for confirmation in early October. The chairman "intends to hold a hearing sometime in September,'' Taylor Foy said.

Republicans had initially hoped to have Kavanaugh confirmed before the Supreme Court session starts in the first week of October, but they have since shifted their timeline to say he will be confirmed before the Nov. 6 midterm elections.

Some senators want to scrutinize the paper trail of Kavanaugh's public record, to look at the Supreme Court nominee's views on gay marriage, abortion and executive power, fearing it could tip the nation's highest court to the conservative right for years to come.