Act is calling on other parties to allow the public to determine the future of New Zealand's taxpayer-funded superannuation scheme through a series of referendums.

Speaking at his party's annual conference, Act leader David Seymour said it was time to end the " Mexican stand-off" between National and Labour.

"It is vital that we ensure NZ Superannuation is viable over the longer term, avoiding undue fiscal stress and pressure on tax rates, and achieving fairness across generations.

"National won't address the issue. Labour tried and are now backing away.

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"This is a political Mexican stand-off, with the guns pointed at the younger generations."

Mr Seymour noted that the Prime Minister was giving the public the say on whether New Zealand's flag should be changed - a matter that was largely symbolic.

"Why not follow the same process for another intractable problem, one that politicians have been dodging for decades?"

Taking a swipe at John Key and National - Act's centre-right allies - Mr Seymour said "almost everybody" realised that there would have to be changes in current entitlements under the taxpayer-funded scheme eventually.

"We are living longer, and the baby boom generation is starting to hit retirement age."

On current settings, the cost of NZ Super would rise from the current 4 per cent of GDP to close to 8 per cent by 2060, with most of the increase happening in the two decades to 2030.

Mr Seymour said superannuation policy had to adapt to people's increasing life expectancy.

However, there were other issues to consider and options to weigh, such as provisions for those unable to work past the age of 65, whether there should be some element of means testing, indexation issues, the relationship with KiwiSaver arrangements, the possibility of flexible starting dates for taking up superannuation, and the arrangements for new migrants and citizens returning after decades away from the country.

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"The best option is, as with the flag referendum, to establish an independent body to consult with the community and establish a range of options on which voters can express a view in a referendum."