The federal coalition is demanding Prime Minister Julia Gillard come clean on the state of Australia's finances during a keynote speech in which she is expected to flag cuts to so-called middle class welfare.

In her address to the National Press Club on Wednesday, Ms Gillard is expected to outline structural spending cuts and hits to the wealthy to pay for big ticket items like the National Disability Insurance Scheme (NDIS) and schools funding reform.

She will also hint at cuts to, or the axing of, handouts for upper and middle class voters, such as family payments and superannuation-related tax concessions.

"We will make the tough necessary decisions to ensure our medium-term fiscal strategy is delivered and our centrepiece plans for Australian children and Australians with a disability are funded in this new low revenue environment," Ms Gillard will say.

Opposition Leader Tony Abbott, who was continuing a mini-campaign on Wednesday, challenged Ms Gillard to come clean on the government's budget position after last year's ditching of its promised surplus for 2012/13.

"Tell us exactly what the budgetary position is," Mr Abbott said in Melbourne.

"She must tell us what the current state of the books is and what the budget deficit is going to be this year," he told reporters.

If Ms Gillard failed to disclose the information, her speech would just be "spin and hot air", he added.

"The underlying question the prime minister always faces is trust," Mr Abbott said.

But he declined to say whether he would use his own National Press Club speech on Thursday to make new policy announcements, saying only that "budget surplus is in our DNA".

Shadow treasurer Joe Hockey said when Labor talked about savings it was code for tax increases.

"The bottom line is, under Labor, Australians are going to have to pay more because they waste money," he told ABC radio.

Liberal frontbencher Christopher Pyne said Ms Gillard should use Wednesday's speech to "outline a sustainable economic plan for the country".

"Rhetoric, platitudes - people are sick of them," he told ABC radio.

Disability Reform Minister Jenny Macklin said Ms Gillard would reiterate Labor's determination to deliver the NDIS to help disabled people and their families and carers.

She declined to say how Labor would pay for the reforms.

"You'll have to wait to the budget to see the detail," she told Sky News.

Ms Gillard is due to speak in Canberra around 12.30pm (AEDT).