Prime Minister Julia Gillard during Question Time at Parliament House in Canberra on Tuesday.

Prime Minister Julia Gillard during Question Time at Parliament House in Canberra on Tuesday. Photo: Alex Ellinghausen

Julie Bishop's dramatic escalation of her claims about the AWU slush fund confirms - as if any proof was needed - that the Coalition's strategy is to deny the government oxygen for its own messages in the crucial, final week of Parliament.

It is now clear to nervous Labor MPs that the opposition has no intention of backing down on its campaign against the integrity of Julia Gillard.

Bishop is recycling documents, some long discredited, to keep the issue alive, with forensic probing of the past. She is pushing the boundaries of defamation, probably believing it would not be in the PM's interest to sue.

''[Gillard] created the stolen vehicle that the bank robbers took to the bank, to rob the bank,'' Bishop said on Tuesday.

She went much further with this imagery, in the confines of the Coalition party room.

A writ would close down debate and, perversely, would be used by the opposition to ''prove'' the PM has ''something to hide''.

This type of mud slinging, day after day, is creating a no-win situation for Gillard. Her frustration is showing and her voice is breaking, with rage or frustration, or more likely a combination of both.

This is dangerous territory for Labor as the Coalition's questions are now segueing into allegations.

So far Bishop has used question time for just that.

She has not followed question time with a speech in Parliament, preferring to speak to the media.

Curiously, the opposition accuses Gillard of doing just that.

In Tuesday's question time Gillard repeatedly referred Bishop to transcripts of prime ministerial press conferences and interviews.

The PM again sledged Tony Abbott for not having ''the guts'' to prosecute the allegations..

On Wednesday, Abbott will promote himself as a leader of substance, producing ''A Strong Australia'', a compendium of his speeches.

Voters will be urged to see Abbott as a serious statesman, restrained, not throwing the mud at the PM who labelled him a misogynist.

But Abbott will be sorely tempted to enter the fray on Thursday, the last sitting day of the year, and deliver a strong speech against the PM's character and credibility.

He wants Coalition MPs to leave Parliament for the summer break believing the PM is too damaged to win the election.

But the PM is angry, determined and steely, meaning the final two days of Parliament are shaping up as even more brutal and vicious.

Twitter: @rosspeakeCT