AS dumb things go, it is one of the dumbest things Tony Abbott has said.

It was 2007 and asbestos campaigner Bernie Banton - who had terminal cancer - had called Abbott "a flea". Abbott had dismissed as "a stunt" Banton's bid to lodge a petition backing subsidies for mesothelioma drug Alimta.

"Let's be upfront about this. I know Bernie is very sick, but just because a person is sick doesn't necessarily mean that he is pure of heart in all things," Abbott said.

Ultimately both men conceded they had spoken in haste.

Now, Labor MPs are invoking Australia's understandable anger over the fate of asbestos victims again to attack Julie Bishop, the lead prosecutor in the curious case of the Prime Minister, her ex-lover, a union slush fund and "Bill the Greek".

It's been a slow burn, with Labor MPs including NSW's Stephen Jones laying the groundwork. "As a former lawyer JBish should tread carefully when trawling through the clients that former solicitors turned MPs once worked for," Jones tweeted on October 31. On November 1 he retweeted, "It is long past the time the Government went public on Bishop's history."

And what a Pandora's box of coincidence and historical cross currents there is, as Bishop pursues Gillard over her role in creating a union slush fund when working for Slater & Gordon, a law firm that made history fighting for workers' rights in asbestos cases.

In the 1980s, working under her married name Julie Gillon, Bishop was deeply involved in some of Slater & Gordon's biggest asbestos cases.

Lawyer Peter Gordon told Australian Doctor magazine in 2007: "We had to fight even for the right of dying cancer victims to get a speedy trial. I recall sitting in the WA Supreme Court in an interlocutory hearing for the test cases involving Wittenoom miners Mr Peter Heys and Mr Tim Barrow. CSR was represented by Ms Julie Bishop (then Julie Gillon). (She) was rhetorically asking the court why workers should be entitled to jump court queues just because they were dying."

Bishop denies that entirely. "Absolutely not. At all times I acted on the instructions of the firm's clients, CSR Limited and the state government insurance office. I acted professionally and ethically. I utterly reject Peter Gordon's version," she said. "It would be appalling for someone to draw some moral equivalence between my role in the Wittenoom case and establishing a union slush fund."

Robert Vojakovic of WA-based Asbestos Diseases Society says Bishop "had a take-no-prisoners approach".

Of course, solicitors don't choose their clients. But Stephen Jones thinks Labor should point out Bishop's role. "You can't judge anyone by their clients, I suppose. But she had some pretty dodgy ones in my view."