The new leader of Shoalhaven City Council has hit back at critics who have questioned her ability to perform the dual roles of mayor and federal MP, pointing to others who held dual positions.
Long-serving Gilmore MP Joanna Gash won a landslide victory in Saturday's local government election to become the Shoalhaven's first female mayor.
She will retire from federal politics at the next election, expected late next year, but in the meantime will serve in both roles.
Mrs Gash's election win has again triggered legal questions about whether local councillors also serving as federal MPs should be disqualified under the Australian Constitution, which prohibits people who hold "any office of profit under the Crown" from serving in federal parliament.
Critics have also questioned the ability of MPs to perform in two demanding roles.
University of NSW constitutional law expert Professor George Williams said the legal question had never been tested in the High Court.
Prof Williams said there were similar instances of MPs also serving as councillors, but to date nobody brought a legal challenge.
"Here, though, things might be different, given the hung parliament and given also that the governing party, the ALP themselves, doesn't have this problem," he said. In the case of a challenge, he believed the outcome could fall either way.
A decision against Mrs Gash would trigger a by-election in Gilmore, he said.
"We've had a number of cases dealing with federal parliamentarians holding office of profit under the crown and we've seen people struck out as public servants . . . but we've never seen tested whether you're struck out because you're a local councillor."
Labor minister Anthony Albanese yesterday said he would be surprised if there was not a legal challenge.
He said the idea of serving as an MP and councillor at the same time was "pretty extraordinary".
However, Mrs Gash said there were more than 20 examples of politicians holding dual positions in the history of the federal parliament, including 1940s Labor Prime Minister Ben Chifley.
Labor's David Bradbury served on Penrith City Council for almost a year after he was elected in 2007, while Liberal MP Russell Matheson still serves on Campbelltown City Council, she said.
"Any reservation about precedents is available to be tested in the High Court of Australia," she said.
"The big issue here is why are they suddenly deciding to have a go now. Why didn't somebody say something earlier in the piece?"