ACT wants a binding referendum on the future of New Zealand's superannuation and raising the retirement age.

Leader David Seymour says a public vote would end the "Mexican stand-off" between National and Labour, as pressure on the system grows. He believes it is untenable to keep paying out super from aged 65.

In a speech to his party's annual conference yesterday, Seymour pitched the idea of an independent body to oversee a series of referendums on future of superannuation. And he pointed to an upcoming public poll on changing the flag.

"National won't address the issue, Labour tried and are now backing away. This is a political Mexican stand-off, with the guns pointed at the younger generations," he said.

He was referring to a previous Labour election pledge to raise the age of eligibility.

Seymour added: "If the public can vote on the New Zealand flag, a matter that is largely symbolic, why not follow the same process for another intractable problem, one that politicians have been dodging for decades."

ACT scored just 0.69 per cent of the party vote at September's general election. Seymour is their sole MP, representing Epsom after stitching up a deal with National.

Now an under-secretary to the education and regulatory reform ministers, he became party leader after Jamie Whyte quit following the dismal result.

As the party celebrated its 20th anniversary this weekend, Seymour set himself the ambitious goal of returning to Parliament in 2017 with at least five MPs.

Labour leader Andrew Little confirmed his party's policy of gradually raising the age of eligibility to 67 is still under review.

"There is a bit of bouncing around from one party to the next about what we do," he agreed.

"I certainly don't say it is a bad idea. I just think it would be helpful if politicians, with the help of the public, could have a robust discussion come up with something that we can all agree on and live with so people get a sense of certainty and stability."

Finance minister Bill English did not respond to a request for comment.