Key seat in SA election still in doubt

A former Labor minister still faces an uncertain future as counting continues in the South Australian election.

Leon Bignell, the former tourism minister, leads Liberal challenger Andy Gilfillan by 184 votes with 89 per cent of the vote counted in the seat of Mawson in Adelaide's south.

"All you can do is just relax, you can't win any more votes, all the votes are out there they just have to be counted," he told FiveAA radio on Friday.

Mr Bignell faced a tough challenge to keep his seat after boundary redistribution turned it from a marginal Labor seat to marginally Liberal.

But if he retains his seat, it will leave the new government with 25 seats and Labor with 19, with three independents.

In the upper house, vote counting continues, with the Liberals and Labor each set to take four of the 11 seats up for grabs, with two going to Nick Xenophon's SA-BEST and one to the Greens.

Former upper house MPs Kelly Vincent and Robert Brokenshire have likely lost their positions.