Releasing the government's election campaign costings on Tuesday, Treasurer Josh Frydenberg said $2.3 billion had been committed for 35 policies.

These include more seniors having access to the health concession card, reducing the co-payments for taxpayer-subsidised medicines, and a new policy to support first home buyers into the property market by allowing them to access their superannuation.

To help offset these costs, the government would increase the efficiency dividend on departments and agencies by 0.5 percentage points to two per cent, saving around a further $1 billion.

In total, the forecast $2.7 billion to be saved under the efficiency dividend will be driven by how departments managed their properties, technology, consultants and contractors, and staffing arrangements.

"It's a very safe and reliable way of achieving modest savings," Finance Minister Simon Birmingham told reporters in Melbourne.

"These in no way impact the delivery of services and support to Australians."

Prime Minister Scott Morrison, on the campaign trail in the Northern Territory seat of Lingiari, said departmental budgets totalled $327.3 billion.

"If our senior public servants - and they're paid well - if they can't find $2.7 billion out of a budget of $327.3 billion, well, I've got a lot more confidence in them that they can achieve that," he told reporters.

The savings are on top of the $103 billion improvements in the bottom line flagged in the 2022/23 budget release on March 2.

Mr Frydenberg said this was the result of more Australians being in work and fewer people being on welfare.

It was also the result of conservatively forecasting commodity prices in its economic assumptions.

The budget estimated iron ore at $US55 per tonne, even though it was trading at $US130 per tonne, the treasurer said.

At the same time, thermal coal was forecast at $US60 per tonne when it is trading at more than $US360 per tonne and metallurgical coal was predicted to be $US130 per tonne compared with more than $US500 per tonne at the moment.

"If we were to see that for another six months, it would be worth $30 billion to our budget bottom line," Mr Frydenberg said.

As a result of the election campaign decisions, there will be a minor improvement to the budget bottom in 2022/23 to $77.86 billion from the $77.94 billion as forecast in the pre-election economic and fiscal outlook.

By 2025/26, the deficit is expected to have narrowed to $42.55 billion compared to the $42.94 billion previously forecast.

Labor leader Anthony Albanese was repeatedly asked during an unruly press conference in Perth on Tuesday whether his deficits would be larger, but he refused to say.

"Our costings will be out on Thursday. They'll be released at the same time as the last time that there was a change of government," he said.

In Brisbane, shadow treasurer Jim Chalmers told reporters Labor had been working closely with the independent Parliamentary Budget Office.

"Some of our commitments are capped, some of them come at no cost, some of them are matching the coalition," Dr Chalmers said.

"So what you'll see on Thursday is a tallying of the commitments that we've made."

Australian Associated Press