"We're absolutely appalled at this treaty negotiation," Mrs Vickers said.
"We are concerned that a treaty this important, with such far-reaching consequences, has hardly been heard of by the New Zealand public.
"Kapiti TPPA Concern echoes the sentiments of most New Zealanders - that our democracy and sovereignty is not for sale at any price."
In April this year, following a push from the union, Kapiti Coast District Council passed a 12-point resolution supporting safeguards from, what Mrs Vickers called, "the worst" aspects of the TPPA.
As a result, 12 councils throughout the country followed.
According to Greenpeace New Zealand chief policy advisor Nathan Argent, the TPPA had the potential to impact environmental regulation, workers' rights, health care and intellectual property.
"If New Zealand wanted to introduce better legislation - for example, limiting the amount of waste we produce - the TPPA will allow investors to challenge these decisions in offshore private tribunals."
Otaki National MP Nathan Guy said the TPPA was potentially worth billions to the New Zealand economy.
"It's a chance to cut through many of the barriers our exporters face, like tariffs and quotas.
"What we do want to do is open up markets for Kiwi exporters, and to create jobs for New Zealanders.
"We've already seen what a huge success the China Free Trade Agreement has been, with two-way trade having reached $20 billion, and our exports having tripled."
Otaki Labour electorate committee chairman Rob McCann, who was among the demonstrators, said he agreed that the TPPA could hinder New Zealand's own affairs.
"New Zealand should be able to pass laws that govern our country.
"I'm worried this Government is selling us out, and until such time as the Government trusts the public with the information, I'm not willing to trust them."
Mr Guy said, while the TPPA was being negotiated, New Zealand would not sign up for any deal that was not in its best interests.
