The Peace Action protest outside the Defence Forum at Westpac Stadium in Wellington in 2017 turned chaotic.

Peace action protesters are attacking planned security measures around the Defence Forum in Palmerston North at the end of October as a violation of their rights.

Peace Action Wellington spokeswoman Ellie Clayton said the security plans were disproportionate, giving priority to those attending what Peace Action called a weapons expo over legitimate rights of protest.

In particular, they objected to a road block planned near the Central Energy Trust Arena as a clear attempt to interrupt a protest march.

Peace Action's website encourages protesters to get involved with attempts to "disrupt" the forum.

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Clayton said the group's tactic was "non-violent direct action". "That's not violent. We have not hurt anyone."

She said it was those attending the forum who were "dealing in death and destruction" and Peace Action did not believe their business at the forum was legitimate.

"We are normal people who are really horrified about what's going on in there, with the selling of weapons to be used in Yemen and Syria where people will get hurt."

KEVIN STENT/STUFF There was a strong police presence outside the Defence Forum in Wellington in 2017.

Peace Action Manawatū spokesman Fred Hirst said the roadblock was an outrageous violation of fundamental rights and probably illegal.

The council and police did not have the right to screen people wanting to use Waldegrave St during the expo.

Hirst said the forum was a trade fair for major weapons companies, including Lockheed Martin, General Dynamics, Thales and Northrup Grumman.

"These companies come together at the expo each year to showcase their latest arms and surveillance equipment, carry out business deals, network and plan how to expand their business.

KEVIN STENT/STUFF Protesters face off against police outside the Defence Forum in Wellington in 2017.

"This weapons trade fair has been driven out of Wellington and Auckland because of wide opposition to war profiteering."

Defence Industry Association board chairman Andrew Ford said there was no dealing at the forum, but would not name sponsors for fear of harassment by protesters.

The city council has worked with event organisers on a traffic-management plan around the forum.

It involved stopping traffic at the Cuba St-Waldegrave St intersection, with marshalled checkpoints near the Featherston St access to Waldegrave St.

KEVIN STENT/STUFF Police stand over protesters attempting to block access to the 2017 Defence Forum in Wellington.

Pedestrians on Pascal St would be directed to use the footpath on the opposite side to the entrance to the Arena.

Council road planning team leader David Lane said the measures were designed to ensure the safe movement of people and vehicles.

The road closures would only be partial.

Forum organisers were expecting about 700 attendees, but Lane said they were also expecting there would be protesters, and were putting in place contingency measures that were greater than might usually be expected for an event of that size.

One of the groups affected by traffic control is the Palmerston North Women's Health Collective in Waldegrave St.

KEVIN STENT/STUFF Police remove protesters disrupting access to last year's Defence Forum in Wellington.

Centre spokeswoman Jean Hera said women visiting the centre during the forum were likely to be stopped at a checkpoint and asked about the nature of their business.

"This is going to be so intrusive."

Hera said women with appointments would be contacted and advised what to say, but most visitors just dropped in, and she was worried women needing support would simply stay away.

She was disappointed the city council was allowing the event to go ahead and was a party to plans to restrict people's right to protest.

Hera said the women's collective had a long background of supporting peace issues and believed those claiming the forum was a front for weapons trading had carried out thorough research to support their opposition.