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."