Maintaining the age of eligibility for superannuation at 65 would be a bottom line for New Zealand First in any coalition negotiations after the 2014 election, says leader Winston Peters.
His stance could be an obstacle to coalition talks with Labour if NZ First is the kingmaker after 2014 - Labour has made raising the pension age to 67 a centrepiece of its policies and has sought to embarrass Prime Minister John Key on the issue.
Mr Key has been under pressure for refusing to contemplate raising the age of eligibility for super from 65 to 67.
NZ First meets for its annual conference in Palmerston North this weekend - its first since the resurgent party made it back into Parliament last year with eight MPs. It is looking for more next election and could be a strong contender for coalition talks in 2014.
Asked whether NZ First's position that the super age should remain at 65 was likely to be an issue in such talks, Mr Peters said: "Of course it's a bottom line."
Mr Peters has rejected Labour's calls for cross-party talks on the issue and he said Labour had made a terrible mistake with its super policy.
"If I was advising them on a political level I would ask them, how does this work?
"You're sending out a dog whistle to a future voting group but you are not addressing the problem here and now. The here and now is an economic solution."
Like National, Mr Peters believes keeping NZ Super eligibility at 65 is possible as long as the economy grows.
Mr Key has not ruled out a coalition with Mr Peters in 2014, despite ruling it out in 2008 and 2011.
But Mr Key yesterday said that common ground with NZ First on the retirement age did not necessarily increase the prospect of post-election coalition talks.
Labour leader David Shearer refused to offer a view on whether Mr Peters' bottom line would prove to be an obstacle to coalition talks in 2014. But he said the cost of NZ Super and the age of eligibility remained a central issue for the country.
"I just don't think you can hinge the sustainability and affordability of our superannuation on some mythical growth rate 10 or 15 years into the future. We just don't know what's going to happen. But we do know what's going to happen in terms of people getting older."