SA Liberals have claimed victory after 16 years of Labor rule in South Australia.

Liberal leader Steven Marshall has declared a “new dawn” in the state, during a victory speech in Adelaide.

The win is expected to mean big changes for the public sector, with a pre-election pledge to make public service bosses find savings needed to fund the Liberal Party’s election promises.

The new Liberal government says it will impose a new “efficiency dividend” across all departments.

Before the election, Shadow Treasurer Rob Lucas said there would likely be a “reduction of administrative and back-office functions” to offset new spending commitments, but insisted “frontline services” would be quarantined from any cuts.

He said the dividend would not necessarily involve job cuts, saying: “I wouldn’t accept the notion this automatically means reducing the size of the public sector.”

The Liberals released costings saying they would save $20 million over four years by cutting 50 ministerial staff.

A lot of the cuts should come from the termination of back-fill contracts, which will see current departmental ministerial liaison officers returned to their original roles within the bureaucracy.

But Mr Lucas has alluded to a broader “efficiency dividend”.

“We’ll be seeking to protect frontline services and reducing administrative and back office functions,” he said.

The full extent of the dividend is still under wraps, but it is expected to account for a significant proportion of the Liberals’ pre-election costings.

“The broader categories, essentially, in the end, will be something similar to what [former SA Treasurer] Tom Koutsantonis announced in the December mid-year budget review – an efficiency dividend, which will require departments to produce savings,” Mr Lucas said.

“How they achieve the savings is essentially up to them.”

Mr Lucas says specific savings measures will be identified.

The Liberals had earlier announced a pledge to discontinue an Aboriginal treaty process, which would save “four or five million dollars”.

“We’ll have a range of things, we’ll announce a number of specific programs which we’ll say we won’t continue to fund [but] an important element will be a savings task for an efficiency dividend, which ministers and departments will have to find,” Mr Lucas said.