About 2,000 anti-government demonstrators gathered outside New Zealand's parliament on Tuesday to vent their frustration on a range of issues nearly six months after protesters were forcibly removed from the grounds of the legislature.

The protesters, organised by the Freedom and Rights Coalition, arrived from around New Zealand and assembled on the lawns outside parliament in the capital, Wellington, as politicians worked inside.

People, some with placards calling for freedom, were protesting over a range of issues including tighter environmental regulations for farmers, a government bid to take over regionally owned water assets and now largely removed COVID-19 restrictions.

"Our government, they're not really working for us," said protester Danny Hanif who had travelled from his home near the town of Hamilton.

Hanif told Reuters the government was not listening to people on the issue of the ownership of water assets.

Barriers were erected in front of parliament and there was a heavy police presence around the grounds.

Police in March ended an anti-vaccine protest that had disrupted the capital for three weeks, dismantling an encampment in the same location, towing away vehicles and arresting dozens.

On Tuesday, about 250 counter-protesters also gathered in a bid to counter hate, homophobia, bigotry and disinformation from the far right, organisers of the counter-protest said in a Facebook post.

Prime Minister Jacinda Ardern told reporters on Monday that parliament had long welcomed peaceful protesters and she wanted this to resume. She did not meet the protesters on Tuesday.

Approval ratings for Ardern's Labour party have plummeted this year with support in the latest 1News Kantar Public Poll released this month at 33%, down from 41% at the end of 2021.