WINSTON PETERS: New Zealand first has held its first party conference since returning from the politcal wilderness.

Winston Peters has created the perfect marriage of NZ First touchstone policies with calls for New Zealand to take a hard look at immigrants who get superannuation despite not contributing to the economy.

Recently arrived immigrants were taking advantage of the universal pension scheme, he told NZ First's annual conference in Palmerston North at the weekend.

Singling out "a young couple from China" who could bring in four elderly parents, he said immigrants could arrive in New Zealand at 55, not work for a decade, and receive full super and healthcare at 65.

He estimated there were 22,000 elderly immigrants from countries with no reciprocal pension agreement with New Zealand.

Although he criticised other political parties for being too "barren" to raise the issue, Mr Peters stopped short of saying immigrants shouldn't get the pension.

Immigration and Super have long been vote winners for NZ First and yesterday's comments got Mr Peters headlines.

The superannuation debate has re-ignited hostilities between Mr Peters and Prime Minister John Key, who challenged the NZ First leader in the weekend to rule out working with Labour.

Mr Peters took exception to Mr Key calling him "tricky", and is still smarting from Mr Key's comments on the teapot tape about NZ First's elderly support base.

"John Key said you were dying out, so congratulations for being here," he told about 200 party faithful.

It was NZ First's first annual conference since returning from the political wilderness in November's election with a healthy eight seats.

Before the conference, Mr Peters said that if he "could have smiled a bit more and got over the outrage" of donation scandals in 2008, the party would have "hosed back in".

The smile is back and and the party is clearly buoyed by its comeback but that doesn't guarantee straight answers from Mr Peters.

Reporters were left scratching their heads at a press conference yesterday, when he was asked whether he could work with Labour if it retained its policy to raise the pension age to 67.

Yes, it was a bottom line and NZ First could not go into a coalition with Labour while it retained its policy, but it could if Labour didn't action that policy in the next parliamentary term. "Our position is very, very clear."

Although Mr Peters said he wouldn't rule any party in or out 2 1/2 years out from an election, he appeared to do just that by saying NZ First couldn't work with a party that sold assets.

"Everybody knows it's a bottom line."