A request to appeal has been lodged with Federal Court over the judgment on the Peter Slipper sexual harassment lawsuit.

Mr Slipper's former staffer James Ashby is seeking leave to appeal against the decision that his case was an "abuse of process".

In his ruling last month, Justice Steven Rares declared the predominant purpose of Mr Ashby's case was to cause "significant public, reputational and political damage" to the former speaker.

Justice Rares also ordered Mr Ashby pay Mr Slipper's legal costs.

Mr Ashby does not have an automatic right to contest the decision.

His request will now be considered by the court.

The law firm that represented him in the case, Harmers Workplace Lawyers, was criticised in the judgment and will also seek leave to appeal.

Mr Slipper stood aside from his post last April after Mr Ashby accused him of harassment, including that he made unwanted sexual comments and encouraged him to shower with the door open while staying at the speaker's Canberra flat.