New poll shows Weatherill support drops

Less than a year out from the SA election, Jay Weatherill's support has dropped but the government and opposition are neck-and-neck.

South Australian Premier Jay Weatherill has lost his mantle as preferred premier, a new poll shows. (AAP)

A new poll shows South Australian Premier Jay Weatherill is now trailing as preferred premier in a new poll.

For the first time, voters now favour Liberal leader Steve Marshall as preferred premier, according to a Galaxy poll.

The poll was published a week after the controversial state budget introduced a bank levy and nine months out from the state election.

On a two-party preferred basis, the Labor government and Liberal opposition are on 50-50, while Nick Xenophon's SA Best party could play a kingmaker role.

Senator Cory Bernardi's Australian Conservatives has picked up three per cent of the first preference support.

"With the minor parties attracting 38 per cent of all votes, the allocation of preferences will be crucial in determining the final outcome," Galaxy Research managing director David Briggs told the Sunday Mail.