Anti-vax march sparks one of Parliament's biggest police operations but protesters cooled off before things went awry

As a group, they were louder than they were large, and boy those anti-vaccination protesters were loud, as thousands marched through the capital.

It was one of the biggest police operations Parliament has seen, but just as things looked set to spin out of control, the protesters pulled back. 

Protesters tore through barricades on the front steps of Parliament on Tuesday, raising fears reminiscent of the US capitol riots. But then - because it's not the States, it's New Zealand - they politely put them back up again. 

Several Trump flags were waved, with one person displaying 'M.A.G.A.' which stands for 'Make Ardern Go Away'. But despite the echoes of America, thankfully this was not.

Protesters were armed instead with tennis balls, hurling them at police and the media along with a few chocolate chip cookies and a bit of bile directed at reporters. 

It wasn't just the predictable targets - at one point the protesters also turned on themselves, with exception taken to a dancing protesters who was forcibly removed twice from the inner sanctum. 

Some of the messaging was inconsistent.

"1080 is a diabolical sin that should be banned forever," one man said, while another commented: "Pretty much just sick of our freedoms being taken away from us."

It was delivered en masse, with protesters coming from all over alert level 2 New Zealand. But the welcome mat was not rolled out.

"Get vaccinated you dips**ts," one counter-protester said. 

"It's pretty lame," said another. 

"It strikes me they don't know the proper medical information."

It began with a civil start in Wellington's Civic Square. There were burnouts from the bikkies, and smoke covering Willis St in the CBD, with hundreds descending down the street. 

Anti-vax lawyer Sue Grey received applause as she waved at protesters. 

Both on the scene and behind the scenes this was one of the largest police operations at Parliament.

Police Commissioner Andrew Coster was confident as he arrived at work. 

"We have good plans in place," he told Newshub. "I won't go into the details but I'm happy with where we're at with it."

All precautions were taken.

"I don't think it would be appropriate for me to make any comment on intelligence we've received," House Speaker Trevor Mallard told Newshub. 

A lot of the vitriol from anti-vaxxers was directed at Prime Minister Jacinda Ardern.

"I do run my own social media so of course I get a slice of that but I'm very clear that's not indicative of the vast bulk of New Zealanders," she told reporters. 

The protesters are a tiny minority. Way more people were vaccinated on Tuesday than were marching. But they caused concern nonetheless. 

"I'm obviously concerned. I have never seen Parliament locked up like this," said National leader Judith Collins. 

MPs watched from inside and were warned not to head outside. However, after being spotted at an anti-vax protest in Whanganui last week, National MP Harete Hipango was considering it.

"I could be, you'll see," she said, when asked if she was planning to attend the protest. "I don't know at the moment."

It was quickly kiboshed by Collins.

"I've made it really clear I don't think that's the right thing to do," Collins said. "It's very much an anti-vaccination protest and we don't want to be seen with it."

It wasn't the only protest on Tuesday. Up at the Te Hana border north of Auckland, dozens of protestors blocked the road for about an hour.

It was peaceful until one of the protestors bit a police officer.