Winston Peters' secret talks with Labour's Jacinda Ardern and National's Bill English

NZ First leader Winston Peters had secret one-on-one meetings with National leader Bill English and Labour leader Jacinda Ardern last night as he attempts to make a decision on which he will crown Prime Minister.

Peters met with English almost immediately after the NZ First board left yesterday afternoon following two days of discussions which were originally expected to resolve whether the party would tilt its hat at National or Labour to form the next Government.

Both leaders and Peters were on their own without staff or any of their negotiating teams - the first one-on-one meetings between them.

Labour leader Jacinda Ardern leaves after one on one meeting with NZ First leader Winston Peters. Photo / Mark Mitchell

While NZ First notified media about the timings of the talks between the parties last week, these were held with no notice. In an apparent bid to keep it secret, rather than walk through the complex Peters drove out of Bowen House and then across to the Beehive to try to slip in without being seen.

They met in the same room NZ First and Labour and National had held their talks in last week.

The Herald saw English leave soon after 6pm, after about half an hour in the room. English later confirmed it was just the two leaders in the meeting.

NZ First leader Winston Peters after secret one-on-one meetings with National leader Bill English and Labour leader Jacinda Ardern at Parliament. Photo / Mark Mitchell

Asked what the next steps would be taken to form a Government, English said, "we'll let you know".

"I can confirm I met with Mr Peters, but I won't be commenting on the contents of that meeting."

Ardern was seen leaving about 40 minutes after that. She managed to sneak into the room without being seen by taking a different route to her usual - going through the Beehive rather than the most direct route from her offices in Parliament House.

She took the route the National Party negotiating team usually took, which provides little opportunity for cameras.

Just before the meetings, Peters told media the board was "98 per cent there" on the policy packages that the two parties presented to NZ First, but leader-to-leader talks were needed to resolve other issues.

"We can't make a decision as a party until we've had those discussions."

He did not specify what those issues were but they are expected to include the shape a government might take, any ministerial portfolios and any concerns Peters might have about working with English and Ardern as Prime Minister.

Peters said all the various shapes a governing arrangement could take were still on the table.

Peters said he would try to resolve the talks as fast as possible.

It was still his goal to reach a decision by the end of the week, but that would partly depend on the other parties as well.

"We've got things to finish off as urgently as we can, sorting out differences of calculations and opinions and trying to make sure we've got with both sides a clear understanding so that if we do finalise it we'll know where we've got the agreement rather than having to go away and write it again."

Peters said there was "serious consensus" over the policies put to both sides. "This is a case of policies that survived and those are the ones that will be going into an agreement."

He said once those final details were hammered out, a further board meeting could be held by teleconference rather than in person.

The Green Party has also been on standby for days to hold a Special General Meeting of its 150 delegates to approve its agreement with Labour, which needed support from both the Green Party and NZ First to form a Government. That is now unlikely to take place unless NZ First advises Labour it is its preferred partner.

The party needs at least 75 per cent of support from those delegates and had its agreement vetted by a reference group including former leader Jeanette Fitzsimons to ensure it would pass muster.