WASHINGTON — The woman who has accused Judge Brett M. Kavanaugh of sexual assault is prepared to testify before the Senate Judiciary Committee next week, so long as senators offer “terms that are fair and which ensure her safety,” her lawyer told the committee on Thursday.

The accuser, Christine Blasey Ford, ruled out Monday as a possibility, but also appeared to leave the door open to testifying even if the F.B.I. does not investigate her accusations, as she had previously requested. Her terms for testifying include that the senators must ask the questions — not an outside counsel — and that Judge Kavanaugh not be present in the hearing room while she speaks. The surprise offer was the latest twist in an on-again, off-again negotiation between Dr. Blasey and Senate Republicans, who have scheduled a hearing for Monday and set Friday as a deadline for Dr. Blasey to tell them whether she would attend.

“She wishes to testify, provided that we can agree on terms that are fair and which ensure her safety. A hearing on Monday is not possible, and the committee’s insistence that it occur then is arbitrary in any event,” wrote the lawyer, Debra S. Katz, adding, “Her strong preference continues to be for the Senate Judiciary Committee to allow for a full investigation prior to her testimony.”

Dr. Blasey’s accusations have rocked Washington, upending the confirmation proceeding for Judge Kavanaugh, President Trump’s second nominee to the Supreme Court, only days before he was to receive a vote in the committee. A research psychologist in Northern California, Dr. Blasey — who is sometimes called by her married name, Ford — has accused Judge Kavanaugh of sexually assaulting her when the two were in high school in the early 1980s — an allegation he has vigorously denied.