Federal parliamentary Speaker Peter Slipper has denied sexually harassing a young male staffer and misusing taxpayer-funded Cabcharges.

In explosive claims published in News Limited papers today, 33-year-old James Ashby says he was continually harassed by Mr Slipper since he began working for the speaker in December last year.

He says it is clear the Speaker only hired him to pursue a sexual relationship.

Mr Ashby has launched a Federal Court action, seeking compensation from Mr Slipper and the Federal Government.

The allegations are a new headache for the Gillard Government, which is relying on the independent Speaker's support to retain its parliamentary majority.

News Limited's Saturday papers have detailed some of the claims about Mr Slipper's behaviour.

Mr Ashby - who is gay - says in his first weeks on the job, Mr Slipper requested massages, asked him for graphic details about his sex life and sent him suggestive text messages.

In one of the alleged exchanges quoted by News Limited, Mr Slipper is said to have asked Mr Ashby if he wanted to become "closer", immediately after allegedly sending a sexually suggestive text message.

Mr Ashby also alleges his employer sent him texts signed with an "x" or an "xxx".

Mr Ashby claims he always rejected the advances of the 62-year-old, who is married with two children.

News Limited reports that Mr Ashby stayed at Mr Slipper's Canberra home when he moved to the ACT to take the job at the start of the year.

Mr Ashby's legal statement says Mr Slipper asked Mr Ashby to shower with the door open. Mr Ashby says he refused to do so, but Mr Slipper never closed the door for his showers.

Allegations denied

Mr Slipper was a Liberal MP before becoming an independent to accept the job as Speaker - shoring up the Gillard Government's numbers in the House.

News Limited says the court documents show the Howard government was aware of Mr Slipper's sexual relationship with another young male adviser - and other allegations of sexual harassment - as early as 2003.

News Limited is also reporting claims about Mr Slipper's alleged misuse of Cabcharge vouchers.

Mr Slipper could not be contacted this morning but a statement on his Twitter account read: "The allegations in News Ltd papers are denied!"

Mr Slipper is believed to be returning to Australia from an overseas trip to Eastern Europe and Africa.

The case is due to come before the Federal Court May 21.

Opposition Leader Tony Abbott says the allegations are serious and Prime Minister Julia Gillard must stand down Mr Slipper while the matter is dealt with in the courts.

New South Wales Liberal Senator Arthur Sinodinos is also calling for Mr Slipper to stand down.

"Peter Slipper occupies the most important formal position in the Federal Parliament as Speaker of the House of Representatives and therefore serious allegations like this cast a pall not only over him but also over the office itself," he said.

"I think it's incumbent on the Government, who has taken ownership of Mr Slipper, to do the right thing and ask him to stand aside while these matters are investigated."