Premier Jay Weatherill has released his party’s election promise costings this morning, saying Labor will spend $670 million over the next four years.

He said the spending would be offset by savings of $689 million.

Labor has also costed the Liberals’ promises, which Weatherill said would be a total of $1.05 billion over four years.

He said the costings had been done by Labor, based on Treasury figures, without any independent verification.

He said Labor released its policy document a month ago because “we wanted South Australians to be fully informed about the decision they make on polling day”.

“Just as we released our plan for public scrutiny, our promises and costings will also be available for public scrutiny,” he told a media conference today.

Weatherill described Labor’s spending as “moderate, but it creates jobs for South Australians now and in the future”.

He also attacked Liberal leader Steven Marshall, who has said he will release his costings on Thursday. Weatherill said Marshall was showing “utter disrespect” to the media by running away from questions on his costings.

Before Marshall even began on his quest to restore South Australia’s triple-A credit rating “he needs to find a billion dollars just to pay for what he’s already promised”.

Weatherill said Labor had found $190 million in procurement savings after receiving a report from consultants Ernst and Young.

“There hasn’t been a budget brought down by this Government that hasn’t achieved substantial efficiencies in the process of government,” he said.

On the spending side, Weatherill announced an increase in the maximum energy concession from $844 to $894 from 1 July, at a cost of $10.25 million a year – or about $41 million over the forward estimates.

The difference between the party’s promises, he said, was that Labor’s spending was capital-heavy and light on operational spending; while the Liberals’ were the opposite, largely due to promises on tax cuts.

– reporting by Liam Mannix