Prime Minister John Key has his head in the sand with his block on raising the retirement age and is more interested in clinging to power than addressing serious issues around NZ Superannuation, Labour's finance spokesman David Parker says.

The political debate around NZ Super flared into life again yesterday as United Future leader Peter Dunne's proposal for a flexible age of eligibility came under fire for doing nothing to address affordability.

Act Leader John Banks said rather than debating Mr Dunne's proposal "Act would like to see all parties engage in meaningful discussion about the long-term issue of NZ Super affordability".

But Mr Key said NZ Super was costing less than it did in the 1970s as a proportion of the overall economy. "Is it really that big a deal? Well that's not what the 40-year forecast says. We've built it into our 20-year forecasts at its current funding.


"If you really want to say the magical rate is to keep NZ Super at what it currently costs today then you have to means test, you have to de-link from average wages and you have to raise the age."

Mr Parker said Mr Key's position, including his pledge to resign rather than increase the age of eligibility was "just populism" intended as a vote catcher.

"We know that it's wrong to be spending more on super than education, that it comes at the cost of caring for children, and yet he has got his head in the sand.

"He is avoiding what is a very important issue, and yet still pretends to be fiscally prudent. It's about votes.

"He is not making decisions here in the interests of our country, he's making decisions that are in the interests of the National Party and John Key."