The Labour Party says the Trans Pacific Partnership appears to have failed to deliver for New Zealand with few gains for dairy farmers and potential implications for medicines.
Deputy leader Annette King would not say this morning whether the party would back the deal because details about its contents were "scant".
"[Trade Minister] Tim Groser did say that there would be some ugly compromises," she said. "We would now like to see what those ugly compromises were."
She said the US would be taking the Trans Pacific Partnership (TPP) to Congress and Canada would take it to its Parliament, and New Zealand should also have a full Parliamentary debate on the agreement.
"We now need to have the same sort of openness. The veil has to be lifted now. It's gone on long enough. The idea that we might go to a select committee - why can't we have what other countries are having?"
Labour's five bottom lines for supporting the TPP are meaningful gains for farmers, protection of the Pharmac model, the ability to restrict house sales to foreigners and govern in the national interest, and the upholding of the Treaty of Waitangi.
Out of the details which have been released some far, Ms King said she had concerns about the implications for Pharmac and about the gains for New Zealand's farmers.
"As someone said, we've barely prised the door open on dairy. Most of the gains are in cheese, not milk powder."
Ms King said one of the positives of the deal was a measure which would prevent tobacco companies from directly suing the New Zealand Government if it introduced policies which affected their profits.
She said the tobacco "carve-out" meant Government should urgently pass legislation which would introduce plain packaging for tobacco.
The Government has previously said it would wait on the outcome of court cases in Australia, where the Government is being sued by Philip Morris over its plain packaging regime.
"It should be no problem now," Ms King said. "We can't be sued so instead of waiting for Australia, we should be able to pass that bill before Christmas."
NZ exposed to "significant risk"
Green Party co-leader James Shaw said the TPP "does not look like a terribly good deal".
He said the estimated value to New Zealand of $2.7 billion a year in 15 years' time added just 1.1 per cent to the country's GDP.
"Five years of intense negotiation doesn't look like its yielded much beyond the status quo," he said.
These gains did not outweigh the new risks created by investor-state dispute mechanisms which have been included in the agreement.
"It looks like the balance is that we don't get a great deal out of it but it does expose us to significant risk," Mr Shaw said.
The Green Party co-leader suggested that if New Zealand banned offshore drilling off to protect a Maui dolphin habitat that foreign oil companies could potentially sue the Government.
He urged the Government to release as much detail as possible about the agreement in the 30-day window before the full text could be released.
United Future leader Peter Dunne, whose vote will be required to pass TPP-related legislation, said he was "broadly happy" with what New Zealand had negotiated, even if the dairy sector did not get what it wanted.
He said it was more important for New Zealand to be part of the deal than to be outside of it, and the country now had a toe-hold in previously protectionist countries such as Japan.
"I can remember Prime Minister Muldoon 20 years ago talking about Japan being dragged kicking and screaming into a trade environment," Mr Dunne said.
"Here we are entering into a free trade agreement on a whole range of products with Japan. I think that's terrific progress."
New Zealand's Parliament will not have a vote on the TPP, but it will vote on the specific changes to New Zealand's copyright and patent laws that will follow the agreement.
Mr Dunne said he would "absolutely" support the law changes.
"Grosser owes NZ people the facts"
New Zealand First leader Winston Peters said the Government had failed to deliver the "gold standard" agreement it had promised.
"New Zealand was promised a stretch limo and we're getting a low-price sedan," Mr Peters said this morning.
Details of the agreement were still "sketchy" but New Zealand's meat and dairy industries had "taken a real hit" in the negotiations.
"The fact is we have failed on the crucial exports we rely on - dairy in to the American, Canadian and Japanese markets and beef in to Japan," Mr Peters said.
The New Zealand First leader added his voice to other Opposition parties calling for a full, transparent debate on the cost and benefits of the deal as soon as possible.
"For Mr Groser to say he can't comment because of the Canadian elections in two weeks' time is unadulterated nonsense. He owes the New Zealand people the facts now and a comprehensive briefing now, not sometime after Christmas when everyone is on holiday."