Prime Minister John Key yesterday indicated National might consider working with NZ First should leader Winston Peters make good on his pledge to stand at the next election.
Mr Key yesterday told TVNZ National would decide if it could work with NZ First once Mr Peters confirmed he was standing.
Mr Peters has strongly signalled his intention to contest next year's election, and yesterday he unequivocally confirmed those plans to the Herald.
Asked whether he would be running, he said: "Yes".
NZ First could field as many as 45 candidates but the former MP for Tauranga would not say which, if any, electorate seat he would contest.
When told of Mr Peters' confirmation, Mr Key refused to comment further, saying instead he would only consider the issue if Mr Peters made his plans official.
"If he formally announces I'll make a call on behalf of the National Party whether we want to countenance any potential relationship with NZ First.
"Winston might be saying he's going to run, he might also change his mind. I've got a country to run and a lot of things to do and I'll worry about that if that day ever comes."
Mr Key ruled out working with NZ First before the 2008 election after it emerged Mr Peters had misled the public over a $100,000 donation he received in 2005 from billionaire Owen Glenn.
Asked yesterday what had changed since then, Mr Key said: "Nothing".
"I have a lot of things to worry about, Winston Peters ain't one of them."
Last week's Roy Morgan poll put NZ First's support at 4.5 per cent, not far off the 5 per cent that would give it seats in Parliament if it translated into votes at the election.
Speculation also emerged that former NZ First MP Michael Laws was a possible party candidate in the election.