Three people have been arrested during an anti-vaccine mandate protest at parliament.

More than 50 police formed a ring around the front of parliament edging up to a line of protesters who have linked arms lining up in front of the cenotaph on Wednesday.

People had gathered as part of a part of a convoy which travelled to the capital to protest against Covid-19 vaccine mandates.

While the protest remained mostly peaceful for most of the day, some people reported hearing what they say was heckling towards police and other people not part of the protest.

Wellington District Commander Superintendent Corrie Parnell says the three men arrested on parliament grounds have been charged with obstruction.

The men, aged 61, 57 and 50, have been bailed to appear in the Wellington District Court on Monday, February 14.

She says all three have also been officially trespassed from parliament grounds.

"At this time, these three men are the only people to be issued with trespass notices from parliament since the protest activity began on Tuesday.

"It should be noted police and parliamentary security staff made an approach to identified organisers earlier on Wednesday, on behalf of the Speaker of the House, to request the removal of tents and all structures within Parliament grounds.

"This did not constitute a trespass notice.

"There have been no further arrests or significant incidents on parliament grounds during the evening and police continue to engage with organisers from the different groups present."

Police staff remained on parliament grounds overnight.