The US supreme court justice Brett Kavanaugh is not a “consummately honest person” and “must know” what really happened on the night more than 40 years ago when he allegedly sexually assaulted Christine Blasey Ford, his accuser writes in an eagerly awaited memoir.

A research psychologist from northern California, Ford was thrust into the spotlight in September 2018 as Kavanaugh, a Bush aide turned federal judge, became Donald Trump’s second conservative court nominee. Her allegations almost derailed Kavanaugh’s appointment and created headlines around the world.

Ford’s memoir, One Way Back, will be published next week. The Guardian obtained a copy.

“The fact is, he was there in the room with me that night in 1982,” Ford writes. “And I believe he knows what happened. Even if it’s hazy from the alcohol, I believe he must know.

“Once he categorically denied my allegations as well as any bad behavior from his past during a Fox News interview, I felt more certainty than ever that after my experience with him, he had not gone on to become the consummately honest person befitting a supreme court justice.”