Premier Jay Weatherill has again defended the controversial Gillman land deal, saying the South Australian government will be making decisions which are far more controversial.

The Supreme Court and the auditor general have criticised the processes involved in selling off the land, in Adelaide’s north, to developer Adelaide Capital Partners (ACP) without going to tender.

Mr Weatherill on Tuesday said the deal would create jobs and South Australians needed to wake up to the economic challenges the state faced with the loss of jobs through the closure of Holden.

“About 13,000 are going to disappear through the loss of Holden and we are going to have to do some incredibly controversial things if we are going to turn South Australia around,” he told ABC radio.

“And if you think this (the Gillman land deal) is controversial and this is a challenge, you haven’t seen anything yet.

“We are going to be putting in front of South Australians some very big changes, which I think will cause them to gasp a little.”

Opposition leader Steven Marshall said the premier’s declaration should concern South Australians.

“Mr Weatherill has dug our state into such a big hole that he is willing to enter into deals that the Supreme Court has called irrational and illegal,” he said in a statement.

“Ignoring proper process and commercial considerations when making decisions to sell South Australian assets is irresponsible and dangerous.”

South Australia’s Independent Commissioner Against Corruption is investigating the controversial sale of government land at Gillman.

In a statement on the ICAC website on Thursday, Commissioner Bruce Lander said he was investigating the deal for possible maladministration.

“This is not a corruption investigation,” he said.

“However, should I find any evidence to suggest that there has been conduct that falls within the ICAC Act’s definition of corruption, then I will pursue it.”

The SA government has been under attack over the deal to sell off the land, in Adelaide’s north, to developer Adelaide Capital Partners (ACP) without going to tender.