The New Zealand First board will meet on Monday, party leader Winston Peters says.
The final round of negotiations wrapped up last night, ending five days of back-to-back meetings with National and Labour.
The New Zealand First board and caucus will meet on Monday to decide which party to form a Government with, and Winston Peters says an announcement will be made as soon as possible after that.
Mr Peters had been working around the commitments of some of the board to bring them together.
The members will be flying in on Sunday and early Monday morning.
Asked how long the meeting could last for, Mr Peters replied, "They're booked in for the night if we have to. But if we've done enough work, then the consideration that happens on Monday should take far less than the time we're involved with now."
Mr Peters said his team had worked overnight to get proposals from both National and Labour ready for consideration.
"That includes doing the fiscals as far as we can go, and making sure we have a very clear idea of what we need to inquire of the other parties to make sure that there's no doubt as to the [result] of our discussions."
New Zealand First MPs are currently in an all day meeting today.
So far, there had been no talks of ministerial positions and the party was still working through policy.
"We've been through their budgets and our own and we've got to make sure that we do agree on the figures we're talking about," Mr Peters said.
He expected constant communication between his party and National and Labour through phone and text, but there were no more face-to-face meetings planned.
Mr Peters wouldn't give a precise date or time for a public announcement of his decision, and said it would be as soon as possible after the board met.
"I hesitate to give you an answer to that question because it's extraordinarily difficult to meet timelines.
"Particularly on this matter, if you're jamming a timeline up against a public statement of date, and you compromise the quality of the decision."
Time is of the essence, Mr Peters said.
"The quicker we make it the less chance of it being leaked."
There are nine different governing arrangements and they are all still on the table, Mr Peters said.