Mike Rann, with wife Sasha Carruozzo, denies having an affair with Michelle Chantelois, right. Photo / The Australian Expand

Mike Rann, with wife Sasha Carruozzo, denies having an affair with Michelle Chantelois, right. Photo / The Australian

CANBERRA - South Australian Premier Mike Rann is fighting for his political life after allegations of an affair with a married parliamentary barmaid, who claims to have fallen under his thrall and to have had "fantasy" sex in his office.

Rann, Australia's longest-serving premier who will be running for a third term next March, yesterday described the allegations as absolutely false and claimed their broadcast by Channel Seven on Sunday night and in the latest New Idea magazine was motivated by political malice.

"I have not had sex with her and the idea that I would have sex between meetings in my office in Parliament Office while Parliament was sitting is so patently ridiculous, I would have thought all of you would have known this," he told reporters.

"I can say today that I'll be taking legal action against Channel Seven and New Idea for allegations that are totally, absolutely, untrue."

Suggestions of an affair with Michelle Chantelois first emerged last month after her estranged husband, Richard Phillips, allegedly struck Rann in the face with a rolled-up magazine at a public function, yelling "remember my wife".

The New Zealand-educated Rann denied knowing Phillips, who was charged and will appear in court in two weeks, but said he and Chantelois had shared a close, platonic friendship for several years.

Until Sunday night Chantelois had refused to comment on the friendship. She was paid a reported A$200,000 ($243,000) for the interview, although the amount has not been confirmed.

Rann's political future now depends on making a more convincing argument than Chantelois who, in the absence so far of any supporting evidence, is now locked in a "he said, she said" argument.

Under Rann both the Labor Party and the state have prospered, reflected in the Premier's political longevity and his performance in the polls.

Although his personal standing has been dented in the past two years, Rann's approval rating in July, the most recent Newspoll, still ran at 51 per cent against a dissatisfaction rating of 40 per cent.

Over the same period Labor's two-party preferred vote has nudged upwards, and in July led the Opposition in Newspoll by 56 per cent to 44 per cent.

Senior Labor figures have publicly supported Rann, although some warned if Chantelois' allegations were proven that support would evaporate.

A rough guide to public reaction came in an internet poll by AdelaideNow, which showed almost 60 per cent of those voting believed Rann should step down.