New Zealand First is expected to announce today that it opposes the China free trade agreement, which has also stirred up opposition among several of Parliament's smaller parties.
A full caucus meeting will be held this morning of New Zealand First's MPs, who have until now remained silent on whether their final position will be to approve or oppose the historic deal.
The party is in a unique position because its leader, Winston Peters, is also the country's foreign minister and his role demands that he maintain good relationships with overseas governments.
But after launching a fresh attack on Asian migration last week, Mr Peters' party is set also to ask New Zealanders to seriously consider the merits of the deal they have been handed with China.
A stance opposing the deal would put New Zealand First on the same side of the ledger as the Greens and the Maori Party, which have already announced their opposition.
National supports the agreement, and so does United Future, Act and Jim Anderton's Progressives.
National's backing guarantees that the legislation needed to put the agreement into action will pass through Parliament.
Last night National leader John Key said that at first reading the deal looked a good one.
He said it was an important entree into the "largest growth engine in the world".
Mr Key said it was critical now that the New Zealand economy was competitive enough to maximise the opportunities the deal presented, and he noted other countries like Australia were close behind in negotiating a deal with China.
"The good news part of the story is we now know where we stand in this huge growth engine," he said.
"The bad news is we shouldn't fool ourselves that we'll be on our own for very long."
Three senior Green MPs stood on the steps of Parliament yesterday to oppose the deal while they waved a Tibetan flag in a symbolic gesture.
Sue Kedgley, Keith Locke and Greens co-leader Russell Norman urged Prime Minister Helen Clark to reconsider the deal with China at a time when that country stood accused of unfairly cracking down on unrest in Tibet.
The MPs contrasted New Zealand leaders being "wined and dined" in China with new reports of problems in Tibet.
The Maori Party last week announced it would oppose the trade deal, in a move which appeared to take Trade Minister Phil Goff by surprise.
The party's foreign affairs spokesman Hone Harawira said the caucus had concerns with China's "lack of respect" for human rights and the environment, and until progress was seen the Maori Party would oppose the agreement.
Although the party was told there may be benefits for Maori, the downsides to the deal were "simply unacceptable" at this time, Mr Harawira said.
United Future has said it will back the free trade deal, although leader Peter Dunne made something of a statement about events in Tibet when he refused an invitation to attend the signing of the agreement in Beijing.