Support for Nick Xenophon and his new party SA-Best has plummeted just weeks before South Australia's state election, while support for the Australian Conservatives is surging the latest Newspoll shows.
After outpolling the state government and the opposition in December when SA-Best recorded 32 per cent of the primary vote, the fledgling party's support has dropped to 21 per cent in the Newspoll published by The Weekend Australian on Saturday.
Mr Xenophon's rating as better premier has also slumped from 46 per cent to 29 per cent, just one point ahead of incumbent Jay Weatherill.
While 28 per cent think Mr Weatherill would be the better premier, 24 per cent think Opposition Leader Steven Marshall would do a better job.
The Liberals are leading on their primary vote, which has risen from 29 per cent to 32 per cent. Labor's primary vote also increased, up three per cent to 30 per cent.
The latest Newspoll also shows South Australians are divided over which major party they believe would deliver better energy policy outcomes.
When asked which party would better manage the state's power supply and keep power prices down, 36 per cent said Labor, while 37 per cent gave the Liberals the nod.
But 27 per cent were undecided.
However, 42 per cent believe the Liberals would better manage the state's economy, compared to 38 per cent for Labor.
Support for other parties and independents - including Senator Cory Bernardi's Australian Conservatives - rose from six to 10 per cent.
The state election will be held this Saturday, March 17.