In another twist to the sexual harassment case against Peter Slipper, his accuser wants to keep secret his reasons for why the Speaker's attempt to have the matter thrown out should be dismissed by the Federal Court.

James Ashby, the former media advisor to Mr Slipper, has filed an interlocutory application with the Court, which will be heard on Friday.

The News Limited journalist who broke the story, Steve Lewis, has also filed an interlocutory application with the court, although it is unclear at this stage what it relates to.

Mr Lewis is scheduled to provide to the court material ordered under subpoena on Friday.

Justice Stephen Rares had ordered Mr Ashby to file by July 3 a response to the "points of claim" documents submitted by the Commonwealth and Mr Slipper as part of their application to have the case struck out as an abuse of process.