By Lawrence Hurley and Susan Heavey
WASHINGTON (Reuters) - The woman accusing Brett Kavanaugh, President Donald Trump's U.S. Supreme Court nominee, of sexual assault faced a Friday deadline to decide whether to testify before a Senate panel as Republican lawmakers and the accuser remained locked in a high-stakes standoff.
Kavanaugh, the conservative federal appeals court judge nominated by Trump in July for the lifetime job as a Supreme Court justice, and Christine Blasey Ford, a psychology professor at Palo Alto University in California, have been invited to testify on Monday at a Senate Judiciary Committee hearing.
It remained uncertain as to whether Ford would agree to appear. Chuck Grassley, the committee's Republican chairman, on Wednesday sent a letter to Ford's lawyers giving her until 10 a.m. (1400 GMT) on Friday to submit prepared testimony if she intended to show up on Monday.
A group of about 40 protesters, most of them women, clogged the lobby of Grassley's Senate office on Thursday. Many wore buttons with the words "I believe Dr. Christine Blasey Ford."
They asked to speak to Grassley and were told the senator is in Iowa, according to Marcie Wells of Las Vegas, a member of the Women's March organization that has been outspoken in opposition to Kavanaugh's nomination.
Ford has said Kavanaugh sexually assaulted her in 1982 when both were high school students in Maryland, an allegation Kavanaugh has called "completely false."
Her lawyers said on Tuesday she would testify before the committee only if the FBI first investigated her allegation. The FBI has said it is not investigating, a decision backed by Republicans.
On Wednesday, a lawyer for Ford said her client was willing to cooperate with the committee, but criticized its plan to have only Ford and Kavanaugh testify.
The confirmation fight has unfolded just weeks before Nov. 6 congressional elections in which Democrats are seeking to take control of Congress from the Republicans. Kavanaugh's confirmation would solidify conservative control of the Supreme Court and further Trump's goal of moving the high court and the broader federal judiciary to the right.
Trump's fellow Republicans appear to be counting on her failure to quickly agree to testify on Monday as a boost for Kavanaugh's confirmation chances. The Senate is narrowly controlled by Republicans, who have embraced the idea of a quick vote on Kavanaugh's nomination if Ford does not to testify.
"We got a little hiccup here with the Kavanaugh nomination, we'll get through this and we'll get off to the races," Republican Senator Dean Heller, who is running for re-election in Nevada, said in a call with the state Republican Party on Wednesday, the Nevada Independent news website reported.
Ford came forward with the allegation in an interview published in the Washington Post last Sunday. She accused Kavanaugh of attacking her and trying to remove her clothing while he was drunk at a party when he was 17 years old and she was 15.
Ford's lawyer Lisa Banks said on Wednesday in a statement that lawmakers should include testimony from multiple witnesses to the alleged assault, adding, "The rush to a hearing is unnecessary, and contrary to the committee discovering the truth."
Democrats, who opposed Kavanaugh's confirmation even before Ford's allegation surfaced, pressed ahead with demands for an FBI investigation.
"For this to be a fair, deliberate and open process, we need to let the FBI do its job and allow agents to conduct a full investigation of the allegations bravely brought forward by Dr. Ford," Democratic Senator Chris Coons wrote on Twitter on Thursday.
Republicans backed Grassley's approach.
"Chairman Grassley has done a masterful job, demonstrating firmness and fairness to all concerned, amidst attempts to hijack the nomination process by mob rule," Senator John Cornyn, a member of the Senate Republican leadership, wrote on Twitter.
(Reporting by Lawrence Hurley, Richard Cowan and Susan Heavey; Editing by Will Dunham)