The government has rejected Labour's demand for the text of the Trans-Pacific Partnership free trade deal to be released before it is concluded.

Labour leader David Cunliffe says parliament should be able to debate the pros and cons of the agreement before the government commits New Zealand to its terms.

Prime Minister John Key says the TPP negotiations are being handled in the same way as all the other free trade agreements New Zealand has signed.

"We have a very thorough parliamentary process and when a text has been agreed it will go before parliament, and before a select committee for public submissions," he said when he was questioned in parliament on Tuesday.

"It will need legislation as well, which will go through parliament."

Mr Cunliffe says New Zealand could end up paying more for medicines and might be sued by tobacco companies for plain packaging under the terms of the TPP.

"We need to make sure the public is able to debate those issues," he told reporters.

Labour would reserve its position on the TPP until it had seen the facts and the fine print, Mr Cunliffe said.

Mr Key says Labour is being given briefings on the negotiations.

"We're not playing games with Labour, where we have information, we're sharing it with them and we will continue to share it with them."

The TPP negotiations began in 2007, aiming to expand the existing free trade agreement between Chile, New Zealand, Singapore and Brunei to include the US, Australia, Japan, Malaysia, Mexico, Vietnam, Peru and Canada.

Source: msn.co.nz