The Liberals need to pick up 10 seats to win an election on March 20 next year, a feat rated impossible before allegations of Mr Rann's affair with a married woman.

The claims place the Liberals back in the hunt for electoral success, Associate Professor Haydon Manning, from Flinders University's School of Politics, says.

While unlikely to result in a Liberal government, Prof Manning says the premier's sex controversy could help them pick up some seats at the poll.

"The Liberals were looking at a dire situation given their internal divisions," Prof Manning said on Monday.

"Now it looks like they're in the hunt.

"And that lifts the morale so much for all those candidates out there door knocking and at the supermarkets, and it lifts a bit of money into the party perhaps.

"All of those things lift the morale of the campaign which looked absolutely shot until this bit of luck fell their way."

Former Parliament House barmaid Michelle Chantelois says she had sex with Mr Rann in Parliament House and other locations.

Prof Manning expected Mr Rann to tough out the controversy.

"The premier has got money in the bank, Labor has got money in the bank, to weather this storm out because of that (10 seat) cushion," Prof Manning said.

"The party will unite behind him - there will be plenty who will be a bit disgruntled with that but they will unite.

"But there will be enough voters and in some of those marginal seats you're only looking at 400 to 1,000 voters who, if they change their mind from Labor to Liberal, those seats change.

"In the background to that of course is the absolute dominance of Rann over state politics ends.

"He's no longer able to campaign as he did in 2006 in what was an exceptionally presidential campaign ... it was all about Rann - that ends, that is all out the window."

Mr Rann is not a member of any Labor faction.

But Prof Manning said the dominant Right faction was believed prepared to accept Patrick Conlon, a senior Left figure, as leader.

"It's so much in that world of the perceptions of the party and the powerbrokers, whether they ultimately decide they can shore up the position, probably lose a few seats, but move on with a new premier," he said.