Hundreds of people braved rain in Napier to join a rally to stop the Trans-Pacific Partnership (TPP), making claims a local agreement negotiator says are irresponsible.
In a statement before the march, organisers It's Our Future group said the TPP would "raise the price of medicines, let foreign investors sue our government in shady tribunals, restrict internet freedom, and much more".
The march started at Memorial Square and moved through Napier CBD.
Banners had messages such as: 'TPPA is corporate welfare' and 'Our land, our people'.
The march ended at the Sound Shell on Marine Parade where speakers, including the MP for Napier, Stuart Nash, addressed the crowd.
He said Labour would not sign up to anything that would remove the government's ability to restrict foreigners from buying New Zealand land.
"We will not give up our sovereignty, " he said.
"By signing this agreement, we sign a deal with the Devil.
"We sign away our right to be New Zealanders, we sign away our right to stand up for what we believe in - for the Government to make laws that are in the best interests of everyone. We must retain that right."
The Government drug-buying monopoly Pharmac and the Treaty of Waitangi must be protected "come hell or high water".
Waipukurau farmer and Special Trade Envoy Mike Petersen said unfounded views of the TPP were "irresponsible and verging on scaremongering".
"Our negotiators and I are working very close with them, and working hard for New Zealand's interests," he said.
While Prime Minister John Key admitted New Zealand will have to pay more for medicines if it signs up to the agreement, Mr Petersen said it would unlikely affect individuals.
Extending intellectual property rights was "a two-way street", with New Zealand inventions given added protection.
"People say this is something New Zealand is going to lose from and that is simply not the case.
The net benefits of TPP will be quite significant, right across New Zealand.
"Even when you look at the sheep and beef gains alone we are talking huge benefits for Hawke's Bay."
Access to the Japan market for beef alone would give savings of up to $90 million annually, he said.
Negotiations were very complex - New Zealand was negotiating 11 bi-lateral free trade agreements - but no more secret than other trade deals when under negotiation, he said.
The TPP would cover the United States, Australia, New Zealand, Japan, Canada, Brunei, Chile, Malaysia, Mexico, Peru, Singapore and Vietnam.
So far there were only agreements in principal for TPP trading sectors, which were subject to agreements in other sectors.
"Nothing's agreed until everything is agreed. If we were to divulge our wins and agreements to date, they might be taken off the table."
Recent TPP talks in Hawaii failed to reach a final agreement but trade ministers were optimistic a deal could be struck.
Mr Petersen said the agreement was "literally 98 per cent there". The only outstanding issues were intellectual property rights, automobiles (between Japan and North America) and dairy.
The willingness for countries to give dairy greater market access was "low in ambition" but that could change when the outstanding sectors were agreed.
"I wish we could be more open but it is a very complex and fragile set of negotiations. We have to be just so careful, otherwise things get taken off the table."