A superannuation fight is brewing as the federal government flags the possibility of changes to tax concessions to help ease budget pressure.

Superannuation concessions are on track to cost the budget as much as the aged pension by 2050, and Treasurer Jim Chalmers started a national discussion about their sustainability this week.

But the shadow treasurer says superannuation is not a piggy bank for the government to tax and spend.

Angus Taylor will give a speech in Brisbane on Thursday in which he will argue the government has “no mandate” to tax super.

“These are private savings. Fundamentally super is Australians’ money, not the government’s,” he will say.

Opposition Leader Peter Dutton said the coalition would block any moves by Labor to change the arrangements around superannuation.

“We’d seek to block it in the first instance because it’s clearly a broken promise,” he told Nine’s Today show.

“The difficulty in the superannuation space is that people want certainty around that investment class.

“If you create that uncertainty, then people won’t invest, and the whole idea of superannuation is it provides for people’s retirement so that they can lead a dignified retirement.”

Yet Mr Taylor will flag that the coalition is open to superannuation changes that would allow people to use funds for house deposits.

“With the clarity that super is for retirement, the coalition will support changes that see super work better to deliver retirement outcomes for Australians,” he will say.

“Housing is essential to this.”

Mr Taylor will say changes to superannuation must be predictable, certain and consistent with election promises.

“These are long-term investments, and shifting the goal posts in ways that take away from super, rather than add to it, leaves Australian retirees in the cold,” he will say.

– AAP