Lawyers for embattled union boss John Setka are warning Labor officials to postpone any moves to expel him from the party, as they seek to mount another appeal.

Mr Setka plans to take his fight to the Victorian Court of Appeal, after losing a Supreme Court bid to prevent his expulsion.

His lawyers have now written Labor Party officials, declaring they have been instructed to file an application for leave to appeal against Justice Peter Riordan’s decision in the Supreme Court of Victoria.

Opposition Leader Anthony Albanese has been trying to distance Labor from the controversial CFMMEU official, accusing Mr Setka of bringing the party into disrepute.

However, Mr Setka has been unwavering in his determination to remain an ALP member. His position has been bolstered by the backing of powerful union figures.

The relationship soured after Mr Setka was accused of making disparaging remarks about anti-violence campaigner Rosie Batty. He has denied making the comments.

Soon afterwards, Mr Setka was convicted for harassing his wife.

Senate crossbencher Jacqui Lambie has revealed she cooked Mr Setka a roast lamb to try to convince him to quit.

The Prime Minister delighted in the latest legal twist in the Setka saga. On Tuesday, he told parliament Mr Setka was staging a “sit-in” within the Victorian Labor Party.

“Whether it’s the Setka sit-in, or the walkout of WA factions … the corruption we’re seeing in the NSW Labor Party, the leader of the opposition is presiding over a party that is chaos and confusion and even corruption.”

The Morrison government has seized on the conflict to revive legislation aimed at deregistering rogue unions and their officials.

But Labor claims the Coalition is using Mr Setka as a “stalking horse” to ram through its union-busting laws.

Opposition frontbencher Tony Burke said the legislation would have no effect on Mr Setka, as it would not operate retrospectively.

“They are using Setka as a stalking horse – cover to ram through an extreme and dangerous bill that represents an unprecedented assault on freedom of association and will be weaponised against workers,” Mr Burke said.

He argued the Coalition was falsely portraying Mr Setka as typical of a union movement dominated by “big, blue bovver-boys” who wanted to make trouble.

“That’s nonsense,” Mr Burke said.

“The average union member today is a woman in her 40s who works in aged care.

“These are the kinds of workers – whether they are members of a union or not – who will be hurt by this legislation.”

A Senate committee scrutinising the industrial relations bill is due to report by late October, before the proposed laws are debated in the upper house.

-with AAP