Bill Shorten faces a new challenge with gangland widow and convicted drug trafficker Roberta Williams planning to make a bid for the opposition leader's Melbourne seat at the next federal poll.
"Just when I thought politics couldn't get more interesting," Mr Shorten said on Monday when asked about his prospective new adversary.
Every Australian is entitled to nominate for parliament, including in the contest for Maribyrnong, the Labor leader added.
"I don't blame anyone for wanting to represent the northwest suburbs of Melbourne," Mr Shorten said.
Ms Williams is hoping to be preselected as a candidate for the Australian People's Party but her status as a undischarged bankrupt is likely to hinder her bid.
She spent six months in jail in 2006 for trafficking 8000 ecstasy tablets that were supplied to an undercover police officer.
Ms Williams gained notoriety during Melbourne's gangland wars as the wife of slain underworld kingpin Carl Williams.
Roberta Williams was played by actress Kat Stewart in the TV series Underbelly, which centred around Melbourne's gangland wars.
Carl Williams, a convicted killer, was beaten to death by an inmate at Barwon Prison in 2010 and later buried in a golden casket.