Xenophon says poll slump no surprise

SA-BEST leader Nick Xenophon says he's not surprised support for his fledgling political party has dipped, describing its recent election-favourite status as "too good to be true".

In a Newspoll published two weeks from South Australia's March election, primary support for SA-BEST has slumped to 21 per cent, down from 32 per cent in a similar poll in December.

It leaves SA-BEST a distant third behind the Liberals on 32 per cent and Labor on 30 per cent, although Mr Xenophon is still just ahead of Labor's Jay Weatherill as the preferred premier.

"The Newspoll at the end of last year was too good to be true," Mr Xenophon told reporters on Saturday.

"This just confirms what I've known all along, that SA-BEST is very much the underdog."

Mr Xenophon said the slide in support for his group was the result of a "relentless negative campaign" from the two major parties and other groups including the Australian Hotels Association, which has criticised his proposed poker machine reforms.

But he said with two weeks to go until the election, "anything could happen".

"If a week is a long time in politics, then two weeks can be an eternity," he said.

"The fact is, SA-BEST is still doing better than any other third party in this state's history. If we do a little bit better we can make history."

Opposition Leader Steven Marshall said he wasn't concerned with opinion polls and was just focused on the campaign.

"We've got an election in 14 days and all will be revealed on what the people of South Australia have to say right then," he said.

"We're going to be running every single day between now and then, prosecuting our case."

Treasurer Tom Koutsantonis said the Labor government had a policy of not commenting on polls but noted that they move up and down.

"But what I think is occurring is people are looking behind SA-BEST and lifting up the hood and having a look inside," he said.

"What they're seeing is Liberal Party policies."