The budget surplus for last financial year has come in at $15.8 billion, well exceeding the $9.3 billion that was forecast in the May budget.

Treasurer Jim Chalmers, just back from talks in Beijing on China’s economic outlook, will announce the result on Monday.

The government says the better-than-forecast outcome has been driven entirely by lower spending. Revenue was also lower than the budget anticipated. Areas of savings included the National Disability Insurance Scheme, payments to the states, and various grant programs that don’t exist anymore.

This is the government’s second consecutive surplus. The May budget has predicted deficits for the coming years.

Across 2022-23 and 2023-24 the budget position has improved by a cumulative $172.3 billion, compared with what was forecast in the official Pre-election Economic and Fiscal Outlook, released immediately before the 2022 election.

The government says it has made $77.4 billion in savings, including $12.2 billion in 2023-24.

Payments were 25.2% of GDP in 2023-24. This compared to the PEFO forecast of 27.1%

Chalmers said this was the “first government to post back-to-back surpluses in nearly two decades”. The surpluses hadn’t come at the expense of cost-of-living relief, he said in a statement.

Speaking in Beijing on Friday Chalmers said it remained to be seen whether China’s just-announced stimulus measures would work.

“But we’ve seen on earlier occasions when the authorities here, the administration here, steps in to support activity in the economy that is typically a good thing for Australia – good for our businesses and workers, our industries, our investors, and good for the global economy as well.

"Like a lot of people around the world, we have been concerned about the softer conditions here in the Chinese economy. Subject to the details [of measures] that will be made public in good time, any efforts to boost growth and support activity here is a welcome one around the world and especially at home in Australia.”

Chalmers on Monday is likely to face further questions on the Treasury’s work on negative gearing, news of which leaked out last week.