Mr English said talk of raising the retirement age was "a bit of a distraction'' and the Government had to get on with growing the economy to meet the rising cost.
"This Budget, the cost of national super goes up about half a billion, and that will grow over the next few years. And that needs growth-orientated policies that are going to give us the capacity to meet that demand.''
Mr English said the only feasible way to raise superannuation age was to signal it "well ahead of time''.
Superannuation expert Jonathan Eriksen, who has advised governments and companies on super issues, said the retirement age should be gradually raised to 70 - a change that should have happened 10 years ago.
He said New Zealanders were now working for longer, with the life expectancy of the average 60-year-old increasing by more than five years since 1975.
"If the mortality trends continue then at some stage 67 won't be enough, whereas if you move it out to 70, but over a long timeframe, then everybody can start to get used to it,'' he said.
"The biggest problem is that there's not as many young people coming through to fill those work slots as there are old people retiring. So we actually need to keep people working, to keep the productivity of the country going.''
Mr Eriksen also advocated for lowering the KiwiSaver eligibility age to 60.
"That means that people, if they can't work to 65 or 70, then they can access their KiwiSaver earlier to tide them over until they can access New Zealand super.''
Mr Eriksen there was little will to raise the retirement age because people did not not like change and did not really understand the technical issues.
"But you'd be shocked at how many people are going to get to 65 and not have enough money to support themselves in retirement now, let alone down the track.''
People who worked longer were healthier, more social and had a better lifestyle in retirement, Mr Eriksen said.
"But also they're contributing to the tax take because they're generating revenue.''
The Government would be able to afford the growing cost of superannuation if the economy was going well, he said.
"The problem with that is that there's a global financial crisis, and we think it's unlikely that New Zealand can perform very well when the rest of the global economy is slowing down or is in recession.''
Labour finance spokesman David Parker said there needed to be honesty about the age of eligibility of superannuation.
"Within the forecast period of this Budget, we spend more on superannuation than the total of eduction - that's more than pre-school, primary, secondary, tertiary combined,'' he told Q+A.
"We are actually getting to the point that, through not addressing that issue, we're actually having intergenerational conflicts being set up.''
Mr Parker said Labour would gradually increase the age of eligibility to 67.
Labour had twice offered dialogue with National on the issue and on both occasions had been rejected.
