Police are still refusing to take enforcement action against protesters on Parliament grounds because of fears it will lead to violence, says Police Commissioner Andrew Coster.

Coster is in Wellington giving a media briefing on the demonstrations outside Parliament which are now in their 11th day.

Police pulled back from an ultimatum to tow vehicles yesterday saying they would continue to focus on engagement with protest leaders.

Coster says today "negotiation and de-escalation" was the only safe way to resolve the protest.

"In the current circumstances, enforcement action taken by police runs the real risk of injury to the public, escalation in numbers of people, and a transition away from a largely peaceful protest to violence."

Despite a lack of action, Coster insisted that police had had "constructive engagement with some key protest leaders" following the release of yesterday's statement from the Speaker of the House that all parties in Parliament have united under a clear declaration that there will be no dialogue while illegal activity persists.

"We continue to carefully navigate our options to reopen the roads, but the most desirable way to end this safely, is to encourage open communication channels.

"In our assessment the only safe option at the present point in time is a continued focus on de-escalation.

Yesterday, police estimated more than 400 cars, vans and campervans remained ensconced in several streets alongside Parliament.

Coster said the number of people, structures and vehicles had continued to grow over the past day and police expected a "significant number" of people joining the protest over the weekend.

He said police had recognised the ongoing impact from the protest, particularly on residents and users in the surrounding area, and would increased patrols in the area.

He said a traffic management plan to control vehicle numbers was also being put in place to ensure that fire and ambulance vehicles are able to access the protest site.

Coster said the last count of protesters at the site showed there was about 800 people there.

"We continue to have a baseline of people feeling intimidated, feeling threatened (by the protesters). We are getting reports of that going on, and that is a problem but our judgement here is not to create a bigger problem by the actions we take."

He said he was confident of getting progress with the constructive groups' leaders, and "there is management within the group about people's behaviour".

"The majority of the people involved are peaceful and are behaving reasonably, not withstanding that's an unlawful protest, however, there are some around the fringes, as there often are in these groups, who need to be managed and we are managing that in different ways."

Coster said police were confident in their ability to engage and get progress.

"There is a genuine acknowledgement in the conversations we've had today that there's an opportunity for the protest to respond to the announcement that the speaker has made. This is a large group and clearly we need to take the time to let those conversations filter through."

Towing vehicles, a previous option for traffic management that police explored, would run the risk of escalation, but it was still available as an option in their "toolkit", he said.

"It was clear following our announcement of towing on Wednesday that there was a growth in the number of people in and around the site, and a likelihood that those tactics would be frustrated by support mobilising from outside the protest site, people responding to social media etc."

He said police were satisfied with the staffing levels at the protest site.

"We have dramatically lifted the number of staff undertaking patrols in and around the area over the last few days."

About 136 police staff around the country were affected by Covid-19, he said. Coster believed three of those were in Wellington.

"We have had some staff working on the operation affected by Covid, we are working on whether or not that relates to their duties there or indeed other contacts they've had."

- RNZ