WikiLeaks has released another batch of secret documents which critics say show New Zealand is pushing for deregulation in world trade negotiations.

Photo: RNZ / Alexander Robertson

They said the documents showed the Government wanted to loosen its control over public services such as transport, education and water, and in the financial sector.

Photo: Auckland University

The 17 leaked documents are from the highly secretive Trade in Services Agreement, which involves the world's most powerful countries.

The agreement aims to set trade rules and decide how services are regulated in 23 countries, including the US and Australia, and in the European Union.

It is part of what has been dubbed the 'T-treaty trinity', which includes the Trans-Pacific Partnership and the Transatlantic Trade and Investment Partnership.

Auckland University law professor Jane Kelsey said the leaked documents showed New Zealand had been the most aggressive nation in putting commercial interests ahead of environmental, social, and cultural impacts.

"Part of it's ideological, which is pushing the light-handed, risk-tolerant approach to regulation, which we know has failed us here if we look at areas like finance companies or Pike River or the aged care system," she said.

The Prime Minister said he would not discuss the leaks, but said Professor Kelsey was usually off the mark when it came to free trade agreements.

"If you look at pretty much every FTA we've every done, they've always out-performed and done better than we thought and ironically Jane Kelsey has pretty much been opposed to all of them - her fundamental position is opposition to trade," he said.

"We'll make sure in the end that we do the best deal we can for New Zealand."

Green Party, CTU question secrecy

World leaders have met 11 times over the past two years, but the negotiations are supposed to remain secret until five years after any agreement comes into force, or negotiations end.

Council of Trade Unions policy director Bill Rosenberg said that was ridiculous.

"They're as important as any legislation, arguably more important than any legislation that goes through our parliament," he said.

"We'd be up-in-arms if any legislation could be put into effect without us having any ability to have a serious look at what is in it."

Green Party leader James Shaw said the cat was already out of the bag.

"We have been saying for a long time that the Government should release the texts," he said.

"When the public - the only version they receive is via WikiLeaks - you just don't know what version of the truth you're getting."

First Union general secretary Robert Reid said the negotiations were a backdoor to widespread deregulation.

"This not only facilitates privatisation, but the deregulation of services and gives carte blanche to big financial institutions and multinational corporations to come in, buy up, charge what they like... without the Government having any say any more," he said.

The next round of negotiating is set for a month's time in Geneva.