Federal Speaker Peter Slipper should not be allowed to reclaim his post even if the legal woes currently hounding him eventually developed into his favour, Coalition lawmakers said.

Former Liberal colleagues of the embattled Mr Slipper, presently on leave, are convinced that the Parliament's presiding officer is now bereft of moral authority to return to his old job and perform speakership duties.

This in light of recent revelations from court documents that showed the speaker sent unsavoury text messages to his former staff James Ashby, the same man waging the sexual harassment case against Mr Slipper.

The foul languages and sexist remarks from Mr Slipper were proofs that the speaker's position is "absolutely untenable," Opposition Leader Tony Abbott said on Tuesday.

Speaking to reporters, Mr Abbott added "we're aware of some of the absolutely gross descriptions and the foul language that this particular individual seems to have habituated to."

He further claimed that the Coalition was in the process of easing out Mr Slipper from the Parliament prior to the Labor's move of promoting him to the speaker's chair in 2011.

So the ball is now at the hands of Prime Minister Julia Gillard, Mr Abbott said.

"Peter Slipper is (Ms Gillard's) creature, her problem . . . she has to deal with it," the Australian Associated Press (AAP) reported the Coalition leader as saying on Tuesday.

And addressing the Slipper question, according to Deputy Opposition leader Julie Bishop, will serve as an important test for the prime minister.

"It will make it very difficult for any woman to pay respect to Peter Slipper in the role of Speaker, knowing the views he has of women and the offensive and disparaging statements he makes about them," Ms Bishop told Fairfax Media in an interview.

She was alluding to one text message from Mr Slipper, with the speaker allegedly referring to Liberal frontbencher Sophie Mirabella as an "ignorant botch."

The prime minister, however, has insisted that the Peter Slipper matter should be decided wholly based on the outcome of the court case, which the speaker has petitioned for dismissal, arguing that it has become an abuse of court process.

Regardless of the result of his legal battles, Mr Slipper, according to independent MP Andrew Wilkie, should voluntarily leave his chair.

"Peter Slipper needs to have the good sense to resign the speakership and sit on the cross-bench until all criminal and civil allegations against him have been dealt with," Mr Wilkie said in a statement.

And if the speaker turned out insensitive to the sentiments of his colleagues, "the prime minister and opposition leader need to put aside their political differences and have the parliament elect a new speaker," MP Denison added.