Treasury's forecast that the cost of national superannuation will increase by 33 per cent over the next four years shows the "urgent need" for the government to consider raising the pension age, Labour says.
The half year economic and fiscal update released on Tuesday puts the cost at $9.58 billion this year, increasing to $12b in 2016 and $12.68b in 2017.
Labour's policy is to raise the age from 65 to 67 over 12 years, starting in 2020.
The government won't even discuss raising it because Prime Minister John Key said before the 2008 election he would resign from parliament if there was any change under his watch.
Labour's finance spokesman, David Parker, says the forecast is "astonishing" compared with increases of seven per cent for education and three per cent for health over the same period.
"In 2016/17 the cost of superannuation will be more than the entire education budget," Mr Parker said on Wednesday.
"John Key seems to believe he can keep his head in the sand about the huge increase in super costs and hope a future government deals with it."