South Australian Premier Jay Weatherill has visited Government House to dissolve parliament and officially launch the state's four-week election campaign.

The March 15 election will be the first time Mr Weatherill has contested an election as leader.

Labor is hoping to be re-elected for a fourth term and will need to defeat Liberal leader Steven Marshall, who has promised a review of government expenditure.

Mr Weatherill says his campaign will focus on employment and rebuilding the state's economy.

"There can't have been a more important election in my lifetime here in SA," he said.

"This election will be about jobs.

"We are at a crossroads here in SA. We need to build the new industries, create the new jobs and do so with a renewed sense of urgency."

Opposition will create jobs, stop waste: Marshall

Steven Marshall says the opposition's policies will alleviate cost of living pressures.

Opposition Leader Mr Marshall says South Australians have been let down by the Labor Government and his team offers a "fresh approach" to government which will put voters first.

"The choice is very stark," he said.

"We can have four more years of Labor mismanagement of our economy and, of course, the Labor Party has descended into complete disintegration at the top level, or you can have a fresh approach under a united Liberal team to get South Australia's economy back on track.

"We have got a very strong and positive action agenda to rebuild our economy here in South Australia."

Weatherill plans to invest in existing SA industries

Speaking to the media after visiting Government House, Mr Weatherill outlined Labor's plans to further invest in existing South Australian industries such as food and wine, defence and resources.

However, he says the loss of 400 jobs at Holden's Adelaide factory is going to hurt his campaign.

"The economy of South Australia, like all of those great industrial states that rely on manufacturing, is going through enormous transformation," he said.

"The way you respond is to invest, to keep building, to build the infrastructure, to build the investments in these industries to allow them to transform and grow.

"That is the way in which we are going to create jobs in this economy."

Marshall to focus on employment and cost of living

Mr Marshall says the Opposition's policies, to be announced throughout the campaign, will focus on creating jobs and alleviating cost-of-living pressures.

He says the Liberal Party would ask the Productivity Commission to look at the state's expenditure and identify opportunities for cost savings in the budget.

"We will set the scope for the Productivity Commission. We will be setting an upper limit in terms of public sector cuts and we will announce that in the next 28 days," he said.

"If they say health has too many bureaucrats but that goes beyond your scope, you will have an inefficient government to keep your promise.

"This is the whole reason to have a Productivity Commission to take a holistic approach. If we have got wasteful expenditure in one area, well, sure, we would like to trim that area. There is plenty of opportunity for more frontline staff across South Australia."

Mr Marshall says he expects the election result to be close.