Five months after failing to secure government at the South Australian election, the state's Liberal Party is still crying foul.

Liberal won 53 per cent of the two-party preferred vote in March's election, but failed to win key marginal seats.

State Liberal Party president Robert Lawson used its annual general meeting (AGM) in Adelaide to lash out at the result and called Premier Jay Weatherill's minority government "undemocratic and illegitimate".

He said the so-called "fairness provision" in the Electoral Act was a spectacular failure and the Liberals might seek to have it changed.

"There is an argument that section 83 is flawed and that it should be either replaced or supplemented by a top-up system, under which a party which receives 50 per cent plus one is allocated sufficient additional members to enable it to form government," Mr Lawson said.

"Such a change would require legislation to be passed by both houses of Parliament.

"The parliamentary party is developing a policy on this topic."

Mr Lawson said electoral boundaries favoured Labor and disadvantaged the Liberal Party.

Prime Minister Tony Abbott arrives at the SA Liberal Party AGM in Adelaide. ( ABC News: Nick Harmsen )

Prime Minister Tony Abbott also spoke at the meeting and said the Liberals should have won the state election.

"That's why I'm here, above all else, to remedy that wrong," he said.

He lambasted the state's Labor Party for its ongoing criticism of the federal budget, but he also took the chance to applaud police for their actions at a student protest at the University of Adelaide on Thursday night.

"There were about 400 of my friends inside the lecture theatre and about 500 of my friends outside the lecture theatre," Mr Abbott joked.

"And thanks to the wonderful white horses of the South Australian police, none of my different groups of friends met on that particular night."

Several students were injured after breaching a security fence that had been erected around the lecture theatre, but no arrests were made.

Also at the AGM, Opposition Leader Steven Marshall told of his intent to turn the old Royal Adelaide Hospital into a health tourism precinct when it became vacant in 2016.

Mr Marshall said the old hospital was an asset that should not be wasted.

He said Adelaide's burns unit was world class, along with its craniofacial unit and its work in ophthalmology.

"We've got a once-in-a lifetime opportunity to create a world-class precinct here in South Australia," he said.

Mr Marshall said the site could become the southern hemisphere's equivalent of London's Harley Street, which is noted for its large number of private medical providers and specialists.

The State Government has already announced plans to build a second CBD high school on part of the site in Adelaide's East End, but it has not yet decided how to utilise the rest of the land.

Editor's note: (September 10) the article incorrectly stated Labor won 53 per cent of the two-party preferred vote.