Labour Leader Andrew Little says his party is not in a position to oppose the Trans Pacific Partnership deal, but a Labour government would flout some of its terms.
Mr Little said the Government had committed New Zealand to the 12-country trade deal and Labour would not pull New Zealand out of it because it does appear to offer some benefits.
"The National Party has committed us to the TPP. It doesn't matter what we say and do, New Zealand is going to be party to the TPP," he said.
But in key areas, such as a requirement to let investors from TPP countries buy New Zealand homes, a Labour government would say no.
"When we are in government, our bottom line obligation is to citizens of New Zealand. And for our government to act in the best interests of New Zealanders."
He committed to legislating to prioritise New Zealand house buyers, even if it was in breach of the TPP.
"There are some things in this which go against New Zealanders' interests, and we will make sure this doesn't continue. We will have a fight with the TPP parties [about it]."
The text of the TPP deal is not expected to be made public for several weeks, but Mr Little and senior MPs were given a two-hour briefing yesterday by the Trade Minister, Tim Groser.
He said the Trans Pacific Partnership agreement was not the gold standard deal the government claimed, but also it was not the fearsome monster claimed by others.
Mr Little said the briefing was helpful, but there were many details even the government wasn't clear on.