Trade ministers are meeting in Hawaii for the final negotiations which will make or break the Trans-Pacific Partnership Agreement (TPPA).
Under the deal, Prime Minister John Key has admitted the cost of medicines could rise – and if that is the case, Labour says it won't support it.
3 News political editor Patrick Gower told Paul Henry it is a "real admission" by the National Government.
"It's now just a case of what else is in there I guess."
Gower says if New Zealand is not going to get sufficient concessions on dairy and food through signing the deal, it is not worth it.
"If you look at the opposition to the TPP in New Zealand, it almost exclusively comes from the left," he says.
"Canada, for instance, their dairy farmers are protesting against the TPP… because they want to protect their extraordinarily high tariffs."
Watch the video for the full segment.