A prediction from a former New Zealand First MP that Winston Peters will decide to go with Labour and the Greens.

The New Zealand First leader has delayed his decision on the coalition government, saying the caucus and board of the party will decide in the next few days.

Neil Kirton told Mike Hosking he thinks Winston Peters will make his announcement on Sunday, with a number of his colleagues sitting around the Cabinet table.

"I think we will see Jones going in, Peters going in and particularly Ron Mark going in. There will be a couple, perhaps one outside Cabinet."

He said ultimately the decision comes down to Mr Peters but he's doing exactly what's expected of him in an MMP environment.

"189,000 people voted for New Zealand First and...he's representing them to the fullest in this, their vote actually counts."

LISTEN ABOVE AS NEIL KIRTON SPEAKS WITH MIKE HOSKING