Christopher Luxon keen for cross-party support on compulsory Kiwisaver

The Prime Minister believes it would be difficult for other parties to argue against the KiwiSaver changes National is proposing, and is keen to see some cross-party buy-in.

On Sunday, Christopher Luxon announced National would campaign on making KiwiSaver compulsory, if re-elected.

It would also automatically enrol babies and contribute $1500 as a Baby Boost payment, and make employer contributions for workers over the age of 65 compulsory.

National leader Christopher Luxon told Morning Report there had been a "good conversation" taking place over KiwiSaver over the last couple of years, and he had observed the success of compulsory programmes in countries like Australia.

"There are things that we can do to improve the programme and make it even stronger, so that actually, irrespective of your background or your circumstances, everyone's got an opportunity to build wealth over time," he said.

"The sooner people get invested in the KiwiSaver and the compounding returns they get over their lifetime, that just sets them up for a much better retirement."

The party is also campaigning to lift the default rate, and it is likely National will also propose raising the superannuation age.

Luxon said there was no plan to change the universal superannuation settings.

"We are big believers in universal superannuation. We do not want to muck around with that."

Coalition partner New Zealand First, which also has a policy to make KiwiSaver compulsory and introduce a newborn payment, said National was "copying" the party, while ACT leader David Seymour had questions over National's previous plan to lift default contributions.

On the other side, Labour leader Chris Hipkins pointed to National's history of cuts to KiwiSaver, saying National "don't have a leg to stand on."

But Luxon said parties should "step back, take the politics out of it," and questioned why people would argue against things like increasing contribution rates or baby bonuses.

"Reasonably, it doesn't matter which political party you come from, can we get some agreement or some commonality or buy into those things? And I think they're quite common sense things, they strengthen the program, they make it ultimately fairer for people upon retirement."

He acknowledged National had scrapped the kick-start payment in 2015, but this was now a different party.

The changes would come from Budget operating allowances, and were modelled to cost around $300 million a year.

Luxon was confident the promise could be funded.

"We've worked well within our operating allowances, we have a two and a half billion dollar operating allowance. We've come slightly under it, I think, every year for the last three years. So, we've got credibility in managing the finances and delivering it within that," he said.

"Roughly it's about $300 million a year. We've done it very conservatively in terms of how we've costed it, so it might be slightly less than that. For all good purposes, we're putting that aside."

Earlier this year, former Fonterra chief operating officer and Mercury chief executive Fraser Whineray proposed a series of changes to KiwiSaver, including a $5000 birthright investment.

He told Morning Report there needed to be "consensus on the architecture" of a reset.

"This needs to keep going election after election after election. I mean, someone born next year retires in 2092 and so that's 21 elections worth that they have to trust that the settings will be good for them, and so we really need the cement to be dry on this."