While defending charges over sexual harassment charges filed by staff James Ashby, Australian Parliament House Speaker Peter Slipper continues to perform his duties, but away from the public eye.

Upon questioning of Opposition Senate leader Eric Abetz, Upper House President John Hogg admitted that in his role as senior presiding officer he continues to meet with Mr Slipper as the speaker. However, Mr Hogg clarified that he was not aware if the embattled speaker has met with visiting international delegations in an official capacity which are included in his tasks as speaker and president.

Mr Hogg disclosed that he still meets with the stood down speaker once every parliamentary sitting week. He added that despite Deputy Speaker Anne Burke having officially taken over Mr Slipper's position, he did not meet with her.

Meanwhile, Liberal frontbencher Christopher Pyne dared anyone with evidence to prove he is involved in the sexual harassment case that Mr Ashby filed against Mr Slipper.

He made the challenge amid an admission that he spent about two hours drinking and chatting with Mr Ashby in the speaker's office. Mr Pyne insisted that being in contact with Mr Ashby is part of his job as manager of Opposition business, including liaising with the Speaker and his staff.

Commonwealth lawyers opined that the heart of the sexual harassment case that the 33-year old staff filed against the speaker is Mr Ashby's credibility.

Reports said that Mr Ashby's legal team will call other witnesses to provide evidence of the sexual harassment charge, including doctors and forensic experts who examined Mr Ashby's mobile phone.

The furor created by Mr Slipper's case led Opposition leader Tony Abbott to criticize the manner the Gillard government has handled the sexual harassment charges.

"I think the government should never have made light of it. I think the government should never have been in the business of accusing Ashby of being some kind of political conspirator (and) I think the matter should now be dealt with in the court," The Herald Sun quoted Mr Abbott.