A ruling against the Government not releasing Trans-Pacific Partnership Agreement (TPPA) documents shows a "pattern of disdain" it has for the public's right to know, the Greens say.
The Government says it will consider a High Court judgement ordering Trade Minister Tim Groser to rethink his decision to not make public trade deal documents under the Official Information Act (OIA).
In a High Court decision released today, Justice David Collins quashed Mr Groser's decision, saying it should be reconsidered in light of his findings.
Vocal TPPA opponent Professor Jane Kelsey, along with seven other groups, took a case to the high court for judicial review after the Chief Ombudsman upheld the minister's decision not to make the documents public.
Prof Kelsey said her request was denied "without looking at a single document", with Mr Groser claiming "he knew what they all contained and that releasing them would jeopardise New Zealand's interests".
"The minister's approach epitomises the contempt for democratic processes and accountability that has pervaded these negotiations," prof Kelsey says.
Justice Collins says there was "no lawful basis for the minister to withhold, in the way he did, some of the information requested by Professor Kelsey".
"The [OIA] plays a significant role in New Zealand's constitutional and democratic arrangements. It is essential the Act's meaning and purpose is fully honoured by those required to consider the release of official information."
He ordered officials to assess each piece of information asked for by Ms Kelsey against the criteria for withholding information.
Prime Minister John Key maintains the "blanket principle" to keep the documents secret was sound because the other countries had agreed not to release details.
"We'll now need to have the officials go over and review that [decision] and determine what the next steps are - whether the Government wants to appeal that. And if they don't then there'll obviously need to be a change in behaviour going forward," Mr Key said.
He noted the Chief Ombudsman had also agreed with the Government's stance.
The Chief Ombudsman said the judgement was only in relation to Mr Groser's decision, and any suggestion Justice Collins' decision took into account the merits of the office's ruling were incorrect.
Green Party co-leader James Shaw says the decision shows the practice of withholding information under the Act was against the law and "not good government".
"It's part of a pattern of disdain the Government has for the Official Information Act and the public's right to know.
"I think that what the court decision shows is Tim Groser was inconsistent with the law and that he needs to get his act in line with the law."
Labour leader Andrew Little says the court seems to have set a standard for ministers to meet under the act which is "probably long overdue".
Ms Kelsey says the judgement is "cold comfort" considering the negotiations have now finished, saying Mr Groser's "unlawful approach in circumventing the Official Information Act appears to have achieved its goal".
The 12 Pacific Rim country deal was agreed to last week, though each country involved still needs to get the deal through their respective Parliaments.
It was reached after a last-minute dash in Atlanta following years of negotiations.