Hard to stay clean in so much mud-flinging

When you're throwing dirt, the risk is you can get very grubby yourself. And you can slip in the mud. These were Julie Bishop's experiences on Tuesday.

First, her admission that she had met Ralph Blewitt on Friday to determine whether he had any useful material for the opposition's attack gave obvious grist to the government. Never mind that Julia Gillard knew him for years, and Bishop consorted for 10 minutes. Always awkward if you are caught with an unsavoury character.

Julie Bishop has been dishing dirt. Photo: Alex Ellinghausen

More seriously, Bishop claimed on Tuesday morning that Gillard hadn't opened a file because she, boyfriend Bruce Wilson and Blewitt wanted to hide that an entity was being set up to siphon funds for ''their benefit''.

The implication was that Gillard was to be one of the beneficiaries - something Bishop had to walk quickly away from later. Bishop has been sailing close to the wind in accusing Gillard of being involved in breaches of the law, including creating ''the stolen vehicle that the bank robbers took to the bank''.

The opposition was re-throwing the mud on Tuesday rather than finding new stuff. Tony Abbott's attempt to be ''Mr Positive'' with his upbeat party room speech while Bishop was left with the nasty stuff was a bit too cute.

The government was able to talk all day about the opposition ''dirt file''. It had the visual proof in Monday's picture of Abbott's adviser Peta Credlin talking to Bishop, while holding a file marked Gillard/AWU. Timeline. Full Chronology. Transcripts.

The question now is, does the Coalition spend the last two days of the parliament year on an issue of apparently diminishing returns?