WASHINGTON (Reuters) - Some records sought by U.S. senators about the prior White House service of President Donald Trump’s Supreme Court nominee Brett Kavanaugh will not be available until the end of October, the U.S. National Archives said on Thursday, though it was unclear whether this would delay his confirmation process.

FILE PHOTO: With the U.S. Supreme Court building in the background, Supreme Court nominee judge Brett Kavanaugh arrives prior to meeting with Senate Majority Leader Mitch McConnell on Capitol Hill in Washington, U.S., July 10, 2018. REUTERS/Joshua Roberts/File Photo

The documents at issue, sought by Trump’s fellow Republicans, relate to Kavanaugh’s service from 2001 to 2003 as a White House lawyer under Republican former President George W. Bush. Senate Democratic leaders have promised to fight Kavanaugh’s nomination, which requires Senate confirmation.

National Archives General Counsel Gary Stern said in a letter to Republican Senator Chuck Grassley, chairman of the Senate Judiciary Committee that will hold confirmation hearings, that although some records could be produced earlier, a complete review would be completed “by the end of October.”

Senate Republicans have yet to schedule a confirmation hearing for Kavanaugh. Taylor Foy, a spokesman for Grassley, said the senator still expects the hearing to take place in September.

Any delay could mean that Kavanaugh, if ultimately approved by the Republican-led Senate, could still miss the Oct. 1 start of the Supreme Court’s term and that the final confirmation vote could take place close to the Nov. 6 U.S. congressional elections.

The documents could be produced earlier via a separate source: the Bush presidential library, which is conducting its own review. A person familiar with the process said that parallel review will be completed by mid-August.

The documents being reviewed by the National Archives do not include papers related to Kavanaugh’s three years as staff secretary to the president, which Democrats have demanded.

Democrats want to know about any involvement Kavanaugh may have had on controversial issues before the Bush White House such as policy toward torture, the Guantanamo Bay, Cuba, detention facility and other matters.

Senate Democratic Leader Chuck Schumer said Democrats also object to the Bush library, rather than nonpartisan archives officials, vetting the documents.

“This unprecedented process appears to be designed intentionally by Republicans to deny the Senate and the American people the information they need to evaluate this critically important nomination,” Schumer said.

Foy said 125,000 pages of the 900,000 in total pages have already been handed over to the committee. “In the end, the committee will have reviewed significantly more records than ever before for a Supreme Court nominee,” Foy said.