New Zealand First Leader Winston Peters, who was the first to take the stand, condemned the agreement.
"It is not an agreement, it is not about trade, and it is a 20-year campaign that has been about allowing international money to come into this country without the capacity of the country's elected democratic representatives to respond to the people's concerns and set the rules," he said.
"They want to set the rules from offshore."
Mr Peters said negotiations on the trade deal would not have been kept secret if they had been in the best interests of the countries involved.
"If this deal was as good as sliced bread, they would have been screaming from the rooftops way back.
"Now that they have so-called signed it, why can't [Prime Minister John Key] consult and tell you what is in it?"
Green MP Julie Anne Genter said the government's assertion that not signing the TPP would have been unthinkable was "just rubbish".
"Whenever we raise criticism about whether the agreement is actually going to achieve what the government says it will, when we raise concerns about the power it gives foreign investors to sue our government, we are told that we are anti-trade - and that is how you know that there is something really wrong with this deal."
She said the Greens' main concerns with the agreement started with the investor state dispute-settlement clause - an instrument of public international law that grants an investor the right to use dispute-settlement proceedings against a foreign government.
Labour's trade spokesman, David Clark, said his party did not and would not support the TPP now that it had seen what was in the agreement.
"We know what is in the text and it is not pretty. This is not a deal that is good for New Zealand," he said.
"We do not believe that it sufficiently protects our sovereignty. [Party leader] Andrew Little has been very clear that in government, Labour will defy some of the TPP measures that are in place."
Dr Clark said Labour would renegotiate parts of the deal if it was elected to power.
"We want to make sure that corporates can't sue when we regulate in the public interest.
"We want to retain the right to restrict farm sales and the sale of houses to non-residents and foreign speculators.
"We want the Treaty [of Waitangi] upheld and we want meaningful tariff reductions.
"Labour cannot support the deal in its current form."
The Paihia rally was organised by Alby Barr from the Whangarei branch of the Rail and Maritime Transport Workers' Union.
