A Dunedin City Councillor hopes anti TPP protesters won't be scared off following visits by police.

Dunedinite Scout Barbour-Evans has described on social media being visited by police, over their plans for TPP protests later in the week.

Police told them it was a national plan to visit known activists around the country.

Dunedin City Councillor Aaron Hawkins, who is aligned to the Green Party, said this could change how people may protest.

"Different people may respond to this in different ways, some may choose to be less public about displaying their political views which I think is sad and unhealthy."

"And if the police are going door to door intimidating known opponents of the Trans Pacific Partnership in case they might be thinking of expressing their disagreement publicly then that's disgraceful behaviour..and rather chilling."

Former Green MP Keith Locke, who's been the subject of surviellance in the past, said Police acted similarly in 1999 when foreign leaders were coming for a major conference.

"They've got all this pressure from possibly America and Australia and Canada and all the countries where trade ministers are coming, to make sure there's no trouble."

He said the police had "got a bit antsy" as a result and were "going beyond their mandate."

"Police shouldn't be treating protesters as somehow illegal or criminal or a law and order problem. Nor should they be keeping activists under surveillance if they are involved in legitimate dissent."

Meanwhile hundreds of Cantabrians have packed Christchurch's Transitional Cathedral tonight to voice their opposition to the TPP.

The door-knocking of Scout Barbour-Evans was the major talking point of the meeting, the latest in a series around the country.

US trade expert Lori Wallach told the meeting she's shocked the government’s tried to clamp down on opposition to the deal.

Reporter Charlotte Lewis-West said that was met with loud applause from a larger than expected crowd.

"With the amount of people standing at the back, sitting on the ground, a few children on knees, there's definitely over 450 there."