Libs fight super tax despite 'little sympathy' for rich

The opposition has vowed to fight changes to superannuation taxes for multi-millionaires, despite admitting there probably isn't much public sympathy for the wealthy.

The government will move to legislate a higher concessional tax rate of 30 per cent compared with the current 15 per cent for earnings on super balances above $3 million.

But the changes won't come into effect until mid-2025, with Labor insisting it hasn't broken its election promise not to touch superannuation because the policy won't come in until after the next federal election. 

Opposition finance spokeswoman Jane Hume admitted there is "not a lot of sympathy out there for people with balances of more than $3 million".

But she questioned the government's figure of 80,000 people being affected, given that the $3 million threshold will not be indexed.

"How many people will it capture in two years' time?" she told Nine's Today show. 

"Who will fall into the net in five years, 10 years, 20 years because that $3 million hasn't been indexed?"

Cabinet minister Tanya Plibersek said nothing prevented a future government indexing the figure, but Labor was not proposing to do it.

"Don't forget, people will have plenty of notice if they decide to save more than $3 million in their superannuation account," she told Sky News.

Finance Minister Katy Gallagher said banking the billions in savings from the change would ease pressure on the federal budget, which helped all Australians.

Senator Gallagher defended legislating the changes this term as opposed to after the election, which would make it harder for an incoming coalition government to stop the tax hike.

"It's normal practice for a government that's made a decision that requires legislation to then legislate," she said.

Questioned on ABC Radio, deputy Liberal leader Sussan Ley declined to say whether those with more than $3 million in their superannuation accounts were doing it tough as the cost of living rises. 

"I'm not here to say who's doing it tough and who's not doing it tough," she  said. 

"Australians deserve to keep more of the money they earn, and the aspiration of Australians is something that we support in the Liberal Party."

The opposition is calling for more clarity on how many public servants and politicians on the older defined benefits schemes would be impacted by the changes.

Ms Plibersek said the government would work through the details.

But, referring to the defined benefit scheme, she said it was "quite proper that people like me are affected in the same way as anybody else".

The coalition has vowed to repeal the legislation if they come to power.