The National party has also experienced a surge in donations after the Labour party appointed a new leader, National's campaign manager Steven Joyce says.

Photo: RNZ

Since Jacinda Ardern was last week appointed to replace Andrew Little, Labour's popularity has surged, with some polls reporting a nine-point boost.

Labour raised more than $100,000 in donations in the 24 hours after Ms Ardern took over the leadership, deputy leader Kelvin Davis said.

He said an additional 600 volunteers had also offered to help the election effort.

Mr Joyce said donations had also poured in to National's campaign following Ms Ardern's appointment.

He said the surge had galvanised National supporters.

"The change in Labour leader, and the ongoing publicity, sort of reminded everybody there's an election on.

"We've certainly had a boost in activity from our volunteers, and also a boost in donations coming in as well.

"One email we put out on Monday generated over $100,000 in 24 hours."

"Most of them [donations] are quite small ... but they all add up - it's all part of the democratic process."

Labour's campaign manager, Andrew Kirton, said the party was aware that, in National, it was going up against a financial juggernaut, but he said Labour could take heart from the large number of smaller donations that were continuing to pour in.

"They're always going to have more - they probably don't need to fundraise at all.

"We know we're up against someone who's going to invest a lot into staying in power."

Mr Kirton said Labour had received nearly $500,000 in donations over the past 10 days.