New Treasurer Jim Chalmers intends to deliver an economic update as soon as federal parliament resumes, prior to handing down his first budget in October.

Dr Chalmers and Finance Minister Katy Gallagher were sworn in on Monday after Labor secured at least a minority government after Saturday’s election.

The treasurer wants to provide a detailed economic update when parliament returns in June or July to encourage a national conversation about the substantial economic challenges Labor has inherited.

“We will only solve these challenges if we work together,” he told ABC radio on Tuesday.

Briefings by Treasury secretary Steven Kennedy and other officials in the past couple of days have confirmed Dr Chalmers’ worst fears.

“We do have a trillion dollars of debt in the budget, there is substantial weakness across the board in the budget because there has been a lot of wasteful spending over the last decade or so,” he said.

Labor has flagged it will cut $11.5 billion from the budget bottom line by ending the waste and the rorts of the outgoing Morrison government and other initiatives, such as making multinationals pay their fair share of tax.

“If there are more opportunities that come from our audit of rorts and waste in the budget, obviously we will pursue those as well,” he said.

“No government can click their fingers and make all of a sudden a trillion dollars of debt disappear.”

But Dr Chalmers sees no reason why Australia should lose its triple-A credit rating, noting that it was a previous Labor government that achieved the top-tier rating from all three major global credit rating agencies.

“There is absolutely nothing about our plans which should, or in my view will, change the way the rating agencies look at our budget and economy,” he said.