A month later, councillors agreed to consider the matter and subsequently voted to "encourage the Government to conclude negotiations on the TPPA and free trade agreements in a way that provides net positive benefits for the Wanganui district and New Zealand".
The TPP is a trade and investment agreement between 12 of the world's biggest economies - including the United States and Australia - and was signed in Auckland earlier this year. It is yet to be ratified by individual countries.
Among the action group's concerns are the council's ability to control water rights, to procure work from local businesses and its support of iwi rights.
"The demands of the TPP threaten all of the above and council needs to do its homework and plan to put measures in place, removing all present weaknesses around these matters before possible ratification of the TPP," spokeswoman Denise Lockett said. She believed some council business would be undermined by the trade agreement and urged council to fight to retain its decision-making power.
"We want them to fight along with Local Government New Zealand to retain control of their council duties," she said.
"Otherwise their job will be tax collectors."
Ms Lockett didn't expect another walkout from councillors this year. "This is election year for local bodies. I don't think they will."
The group is preparing a petition and is collecting names at the Saturday River Traders market.