Prime Minister John Key says he doesn't have a problem with an "informed debate" about national super but there aren't going to be any changes to it while he's in charge.
Opposition parties say the government must respond to a new report which says the scheme isn't going to be sustainable in the future and the pension age must be increased from 65 if big tax rises are to be avoided.
Mr Key said before the 2008 election he would resign from parliament if there was any change under his watch, and he isn't backing off.
"I've spent my career doing what I say and unless there's a damn good reason I'm not breaking that," he said on Monday.
"If I make a categorical promise, I stand by it."
The Financial Services Council (FSC) says in its report the cost of national super will double to 12 per cent of gross domestic product (GDP) by the end of the century and current tax rates would have to increase by 28 per cent to pay for it.
Labour says the government must address the issue and face the fact that the pension age has to be raised, the entitlement must be cut, or taxes must be raised.
Mr Key came to a press conference armed with Treasury data and said that in 1990 the government spent 14 per cent of its total budget on national super.
"In 2007 the figure was 10.9 per cent, so it actually went down," he said.
"And it was 4.3 per cent of GDP in 2007 - France was 12.5 per cent, Austria 12.3 per cent, Japan 8.8 per cent, Poland 10.6 per cent...I could go on."
Mr Key says nothing he's seen indicates any changes are needed before at least 2020.