The Government is breathing a sigh of relief after the latest opinion poll shows there has been no major damage to National's support from the Dotcom saga.

But Labour is also buoyed after last night's TV3-Reid Research Poll became the second poll in a week to show National losing ground.

National was down 1.8 points but retained a massive majority of 48.8 per cent. Labour was up 2.2 to 33 per cent and the Greens were down slightly to 10 per cent.

NZ First failed to reach the 5 per cent threshold required to remain in Parliament without an electorate seat despite being up a fraction to 3.2 per cent.

The Maori Party was down 1.1 to 1.5 per cent.

A spokeswoman for Prime Minister John Key said the poll showed voters were reacting to a Government that was focused on the issues that mattered.

"Not the stunts and sideshows the Opposition is obsessed with."

However, Mr Key was down to 41 per cent in the preferred prime minister ratings, his lowest level since taking office in 2008.

Labour leader David Shearer fell slightly to 8.5 per cent.

NZ First leader Winston Peters was on 5 per cent and Greens co-leader Russel Norman was on 2.4 per cent.

It has been a difficult few weeks for Mr Key who has been in the spotlight over what and when he knew about the Government Communications and Security Bureau's unlawful spying on German internet mogul Kim Dotcom.

His hands-off approach to his ministry has been questioned and he has been forced to admit he did not remember the GCSB's involvement in the case being mentioned at a meeting in February. This week he will have to amend an answer that he gave in Parliament to reflect his "brain fade".

The Government has also been on the back foot after hundreds of job losses being announced in recent weeks and a "job crisis summit" held by Opposition leaders, unions, economists and academics last week to discuss ways to stem redundancies in the manufacturing sector.

The Government has said the only crisis is the one being painted by the Opposition but Labour leader David Shearer said it was behind some of the bleeding of National's support.

"Dotcom and Mr Key's policy of forgetting things [have] undermined him but also the job losses in Bluff, Kawerau, Greymouth.

"It's like every second day there's another set of job losses," Mr Shearer said.

"It's people who are disappointed in John Key and his handling of issues and disappointed with the Government."

A Roy Morgan poll last week put National down 2 points to 41.5 per cent, its lowest level of support in the poll since becoming the Government in 2008.

Labour was up only marginally to 33.5 per cent but, along with moves from the Greens, up 2 to 13.5 per cent, and NZ First, up 1.5 to 6.5, it gave the Opposition block a clear majority.

- © Fairfax NZ News