Xenophon looks to return to SA parliament

Ten years after he left, Senator Nick Xenophon is planning to return to the South Australian parliament, with aims for his SA-Best party to hold the balance of power after the next election in March.

The crossbencher and Senate powerbroker will quit federal politics to stand in his local Adelaide seat of Hartley.

And given his popularity across the state, he will have a strong chance of taking the seat from sitting Liberal Vincent Tarzia.

But Senator Xenophon says winning will be "like climbing Everest without oxygen" and he's expecting the "toughest political fight of my life".

"But I'm up for that challenge because I love our state, our people and I believe that if you are in politics, you should be there to make a difference," he said.

"For my part, it will be a do or die effort."

SA-Best will also field candidates in key electorates, seeking to become kingmakers once the votes are in next year.

But Senator Xenophon won't decide to back the Liberals or Labor until after the poll, although his decision will be based on criteria he plans to outline beforehand.

The state government doesn't seem too worried about a Xenophon return, given his party is more likely to take votes from the Liberals than Labor.

But Opposition Leader Steven Marshall has warned voters not to support SA-Best, saying it would be a disaster for the state if the party helped Labor win a fifth term in office.