Donald Trump and the justice department are asking the US supreme court to toss an $83m defamation verdict won by writer E Jean Carroll after she accused him of sexual assault, saying he cannot be sued for comments he made while he was president.

It is the second time Trump has asked the justices to nix damages awarded by a jury to Carroll, a longtime New York advice columnist and former talkshow host. The supreme court refused in June to hear his appeal of another verdict, for $5m, that found him liable for sexual abuse and defamation.

The latest case centers on comments Trump made during his first term as US president. The justice department wants to invoke the Westfall Act, which shields government employees from being sued for doing their jobs.

“Absent this Court’s intervention, the sitting President is facing nearly a hundred million dollars of personal liability for conduct that was well within the scope of his federal office,” federal attorneys wrote. “That alone deserves this Court’s attention.”