Winston Peters hopes to have options to take to the board by Thursday night.

Winston Peters says he doubts his caucus will be able to make a decision by Thursday night but expects to have options to take to the NZ First board.

Following the fourth and final meeting on Wednesday Peters told media he hoped all of the negotiations would be wrapped up by the end of play on Thursday but he couldn't possibly gather the board before Friday.

"We should (have talks) finished by tomorrow night but it depends on other people as well."

Jo Moir/Stuff Winston Peters tells media he will take "both options" to the NZ First board once talks wrap up.

He said the priority was policy and they were yet to discuss ministerial portfolios or offices.

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"We're not going to think about offices and positions until we're happy with the policy."

KEVIN STENT/STUFF Greens co-leader James Shaw said he was confident he could trust Labour would argue a fair deal on their behalf.

"If we want to pervert the process you start worrying about yourselves...if we haven't got the policies right then the rest of the questions won't arise," he said.

The plan on Thursday was for the party caucus to meet at 8am and then the first negotiation talks would be with National at 9.30am.

Labour's Jacinda Ardern did not stop to talk to media on her way to or from her team's last meeting of the day with NZ First.

STACEY KIRK/STUFF Winston Peters takes updates on day four of government negotiations.

On the way into the 6.30pm meeting she said she still had "plenty of stamina" while walking past reporters.

On her way out of the meeting she kept her eyes averted and did not answer any questions.

When Peters was asked if he would take both options to the board, he said that was the case, and he wouldn't be leaving until there was "serious consensus".

LAURA WALTERS/STUFF Winston Peters says he's never said a bad word about James Shaw.

"You don't want to be going to a vote in these matters. You want a serious consensus - if you haven't got a serious consensus then stay there until you get one, but who wants a 50/50 vote?"

Peters said he'd expect higher than 75 per cent of the board consenting.

Getting that agreement meant "everyone gets buy-in, everybody gets responsibility and everybody has authority for what the party's going to do."

STACEY KIRK/STUFF Greens leader James Shaw says he has faith Labour will be fair to them, despite the Greens being forced out of any negotiations with Winston Peters.

'GROSS MISREPRESENTATION'

Peters has suggested that if a Government was to be formed with Labour, then the inclusion of the Greens as a headline party would be a "gross misrepresentation".

The NZ First leader was responding to questions over whether it was his understanding that the Green Party would be voting to accept the Labour-NZ First deal, or whether they would simply be voting to approve their deal in separate negotiations with Labour.

HAGEN HOPKINS/GETTY IMAGES NZ First leader Winston Peters. The party's board would be consulted on the preferred final agreement before the decision was signed off.

It comes from questions over whether the Greens were at the mercy of Labour to fight their corner in dealings with NZ First.

Emerging from his first discussion with National on Wednesday morning, Peters said good progress was being made.

"We're making huge progress finding out what we agree on, what we don't agree on, what we can still negotiate on and where we might take things into the future by cooperation.

"At the end, you may not have their decision or our decision as to policy - but a mutual decision," he said.

Peters took exception, however, to questions over whether the Greens would have a say in approving his deal with Labour, saying reports of a potential "Labour-Greens Government" over the past three years were wrong.

"Please don't ask me to explain your gross misrepresentation of the political situation in this country for the last three years."

'NEVER A BAD WORD'

Later in the day - following a meeting with Labour - Peters said he had nothing against Green Party leader James Shaw.

"You know full well... I've never had a bad word with him, or about him that you could possibly quote because I've never said something bad about him in my career."

Earlier, Shaw confirmed his trust in Ardern to negotiate a deal that won't see his party locked out in the cold, or pushed beneath NZ First.

Peters has has ruled out including the Greens in partnership talks, forcing Shaw and his team to negotiate with Labour in parallel and in isolation to NZ First negotiations.

As Government talks enter into their fourth day, Shaw emerged from a two-hour long meeting with Labour and said he was confident he could trust Labour would argue a fair deal on their behalf.

But he would not be drawn on questions of whether the Greens would say yes to any agreement placed in front of them.

"Jacinda made fairness one of her principle values in the campaign, I've known her a number of years and, I said this before the election, I trust her and she seems to be doing a good job of it.

"It's got to be a stable and responsible Government that's going to go the full distance in the national interest. Labour are working very hard on ensuring that that happens. That's of paramount concern to all of us," he said.

Shaw said he was confident he would be happy with the deal Labour eventually presented to them, but all the partners had to be "pretty sure" of their Government's direction to ensure stability.

NZ First and the Greens have had an historically strained relationship, with little trust for the other emanating from either side.

LONG NIGHT OF TALKS

Peters began his day in talks with National on Wednesday that have stretched for more than two hours. He headed back into talks with Labour at 12.30pm. That meeting ended about 2.15pm.

Labour and NZ First's negotiating teams got through the material faster-than-expected, he said.

Peters has indicated there was likely to be more than two meetings with each party on Wednesday, as negotiations get to the pointy end and finer policy details make up the crux of discussions. Following his first talk of the day with National, Peters hinted that his party's deposit guarantee scheme was being considered.

"The reality is that if we end up needing that it'd be a very parlous situation, but we still need to consider it."

Talks with both parties were likely to stretch into the night.

Yesterday, he backtracked on his self-imposed deadline of announcing the formation of a new Government by Thursday. A decision was on track to be made by Thursday night, he said. However, that decision was unlikely to be made public then.

The decision would be announced as soon as possible after Thursday night but it also "depends on other parties" and he could not "answer for them".

NZ First's board would be consulted on the preferred final agreement before the decision was signed off. Each relevant party would also have constitutional procedures to carry out before a deal could be approved.

In the case of the Greens, their constitution requires a 75 per cent approval from the party membership through regional delegates.