SA Liberals keen to use parliament numbers

Opposition Leader Steven Marshall has threatened to use the tight numbers in South Australia's hung parliament to possibly bring down the Labor government.

Mr Marshall is not convinced the minority government can serve its full term and will keep the Liberals on a "war footing" to be ready to take over.

The Liberal leader has not shied away from using the numbers in the house to defeat the government on key legislation and possibly issues of confidence, if government MPs are absent for votes without good reason.

"People are elected to serve in the parliament," Mr Marshall told reporters on Wednesday.

"If they're not here when votes are taken, then they do it at their peril."

When parliament returns in May, Labor will have 24 votes on the floor of the House of Assembly, just two more than the Liberals 22.

But that slim majority comes courtesy of independent MP Geoff Brock, who decided to back Labor after the March 15 election.

Labor must also appoint a Speaker while a second independent, Bob Such, is expected to be absent for some time as he battles a brain tumour.

Mr Marshall said he still believed Mr Brock had made the wrong decision and would continue to try to change the MP's mind.

But Premier Jay Weatherill said Mr Brock was committed to the government and his support was not a day-to-day proposition.

"We have a majority and it's a secure majority," he said.

"This government will go the distance."

Mr Marshall has also unveiled the new opposition front bench with no major changes to the line-up he took to the poll.

He said he had absolute confidence in his team.

"They were focused. They were disciplined. They were unified for an extended period of time and I'm going to back them," Mr Marshall said.

Mr Weatherill said the Liberal front bench was a case of the "same old faces bobbing up again".