Only two months after announcing he would quit the Senate to return to state politics, Xenophon has turned the March 2018 state election into a three-way battle for power, with his SA Best party in the lead.

In the state-based Newspoll, published in The Australian today, SA Best recorded 32 per cent of the primary vote, with the Liberals on 29 per cent, Labor on 27 per cent, and the Greens on six per cent.

At the last state election, Labor polled a primary vote of 35.8 per cent while the Liberals achieved 44.8 per cent.

Xenophon is South Australians’ clear preference for Premier, sitting on 46 per cent of the vote ahead of incumbent Jay Weatherill on 22 per cent and Opposition Leader Steven Marshall on 19 per cent.

He said today he aimed to field 20 candidates at the March 17 election.

Newspoll was unable to calculate a two-party preferred vote – an indication of how SA Best’s entry into the campaign has transformed South Australian politics.

The poll of 800 voters conducted from October 12 to December 17 has a margin of error of 3.5 percentage points.

This Xenophon poll is historic. I can’t recall the major parties ever being outpolled by a so called “minor” party. His candidates only have to come second and Labor or Lib preferences will likely give his candidate the seat. 2 Party system under pressure? https://t.co/A9tnAB5Bx3

— bruce hawker (@brucehawker2010) December 18, 2017

The previous state-based Newspoll taken in late 2015 showed the Liberals leading Labor on the primary vote – 38 to 36 – but gave the two-party preferred advantage to Labor – 51-49 – based on preference flows from the 2014 state election.

Xenophon said today the poll showed that South Australians wanted an alternative “from the political centre”.

“I think what it does show is that people are sick of the broken state of South Australian politics, they don’t think much of the major parties and the fact that SA Best, which is basically a start up, a fledgling party with a fraction of the resources of the major parties, is doing this well in the polls, indicates that people do want change and they don’t want change from the left or the right, they actually want change from the political centre,” he told ABC Radio Adelaide.

Xenophon, who has so far announced six candidates to stand at the state election, said he would be announcing more candidates later this week.

He aimed to have 20 candidates in total, “unless there’s a surge, unless we have lots of people going to the SA Best website today”.

The party was running on a shoestring and trying to make the most of its limited resources.

“We are running in seats where we think we have a real chance of winning, of causing an upset, and it’s tough – it’s tough when you’re a start-up party up against major parties that have the backing of either big unions or big business.”

He defended his requirement that each candidate should stump up $20,000 of their own funds to stand for SA Best.

“The 20,000 is basically there to say ‘if you’re going to run a serious campaign you need that order of money to run it’. I’ve put my 20,000 in, as have the other candidates, because running a typical campaign costs much, much more than that.”

Labor minister Peter Malinauskas focused on policy when asked about the Xenophon threat today.

He said any party aspiring to government needed to present a full suite of candidates and policies and the Xenophon party had yet to do that.

The Health Minister said he wasn’t surprised by the Newspoll figures.

“We’re going through a period of disruption in politics and no-one’s immune from it,” he told reporters. “But the focus of the government has to be making sure we’re delivering the services that people expect.”