Trade Minister Tim Groser insists the government will win the political "war" on the TPP deal once the facts and figures can be laid out on the table.

Talks in Hawaii have ended without a finalised agreement. Groser said the nations involved are down to three final issues, and will meet again soon to iron those out.

Groser believes reasonable people are being "whipped up into a frenzy" over issues like pharmaceutical costs and investor-state dispute settlement, by people who oppose the deal for ideological reasons

"Look, this did not reach an agreement for other reasons," he said of the lack of a deal after the latest talks. He says the impasse is down to automotives, intellectual property and dairy.

The Minister said the government is fighting TPP opponents with one hand tied behind its back, as it simply can't provide the real facts and figures while the discussions are still happening.

"We can't state what we know in precise terms to prove our case. But I wouldn't be making statements, and the Prime Minister wouldn't be making statements, along the lines that any increase in our health costs are going to be absolutely manageable, unless we were confident that we could back this up politically when the facts do come out," he said.

"We wouldn't be that dumb actually, politically, to start making these statements when we would be in danger of not winning the political argument later on."

Groser admits opponents of the deal are probably winning the political battle at the moment, but they won't win the war.

"Once I've got a deal to recommend to the Cabinet, and for the Cabinet to then recommend to the New Zealand people through Parliament, I am extremely confident we will win the war. But at the moment all the noise is on the other side."

Agricultural trade special envoy at the talks Mike Petersen claims New Zealand is not backing down - they're not going to be kicked out of the talks either.

"New Zealand and Australia and America are all fighting pretty hard to get better market access for dairy, particularly in to the large consumer markets, and we just need to see more progress in that area if we're going to get an agreement that we can all buy into," Petersen said.

Petersen believes there has been too much time and capital investment put into the deal for it to fail, and he is confident there will be a great outcome for New Zealand.

But the secrecy cloaking the negotiations has been heavily criticised in New Zealand.

Prominent critic of the deal Professor Jane Kelsey, and Consumer NZ, the Association of Salaried Medical Specialists, Greenpeace, and Oxfam are about to go to the High Court seeking details about what's been discussed.

Professor Kelsey is hoping that will help shed some daylight on the process.

"Certainly this outcome makes it more possible for us to argue for the release of further documents before the negotiations are concluded."

Professor Kelsey says either way, more information is needed - and it needs to be clear the level of secrecy around the negotiations doesn't set a precedent for the future.

Kelsey believes the price of this agreement will be high, whether it's in the cost of medicines for taxpayers or the inability to restrict foreign investment in residential markets.

"All of those are costs," she said. "At present there are no obvious benefits on the table."

"They should cut their losses, walk away, and find something more constructive to spend our taxpayers money negotiating."

Kelsey argues everyone is blaming each other in Maui, but the underlying reason for the gridlock is the domestic opposition in almost all the TPP countries.

Green Party trade spokesman Russel Norman is equally critical of the deal and its secrecy, saying the government should reveal what potential consequences would be for Pharmac, the ICT and dairy sectors, and for investor-state dispute settlements.

"The reason they don't want to tell us is because it will be very unpopular if people found out what John Key and Tim Groser are up to," Norman said.

"If [they] think this is such a great deal then why won't they tell us what's in it? Let's see what's in it so New Zealanders can judge."