National has gone up in the lastest 1 NEWS Colmar Brunton poll, while Judith Collins has overtaken Simon Bridges in the preferred Prime Minister stakes.

The result had National on 44 per cent, up 4 points from the last poll in February, while Labour has dropped 6 per cent to 42 per cent. The Greens are steady on 6 per cent, while New Zealand First has gone up 1 point to 5 per cent - right on the threshold to enter Parliament without an electorate seat.

Act, the New Conservatives and the Opportunities Party are all on 1 per cent.

Collins was on 6 per cent in the preferred Prime Minister states, ahead of Bridges on 5 per cent, both well below Jacinda Ardern on 45 per cent.

In contrast, the Newshub-Reid Research poll has Simon Bridges and the National Party dropping in support.

National has fallen down to 37.4 per cent, down 4.2 points, meanwhile, Labour has skyrocketed to 50.8 per cent, up 3.3.

The results from the Newshub-Reid Research poll would mean the Labour party could Government by itself.

In the 1 NEWS Colmar Brunton poll, Labour and the Greens would still need New Zealand First to form a Government.

The last Newshub Reid Research poll was in February and showed that National had nosedived to its worst result in more than a decade, sitting at 41.6 per cent.

Labour was on 47.5 per cent in that poll, and could govern alone with the Greens on 5.1 per cent; New Zealand First was on 2.9 per cent.

That poll had Jacinda Ardern at 41.8 per cent in the preferred Prime Minister stakes, well ahead of Simon Bridges on 5 per cent, who was below National MP Judith Collins on 6.2 per cent.

Bridges had a similar rating in the last 1 NEWS Colmar Brunton poll, also in February, where he had 6 per cent support in the votes for preferred Prime Minister, the same as Collins and well below Ardern's 44 per cent.

That poll had Labour on 45 per cent, National on 42 per cent, the Greens on 6 per cent, and New Zealand First on 3 per cent, below the 5 per cent threshold required to win any seats in Parliament without an electorate seat.

Ardern has dominated headlines in the past months following the Christchurch terror attack, implementing gun law reform and starting a Royal Commission of Inquiry into how it happened, and whether it could be prevented.

She also scrapped any plans for a capital gains tax while she remained leader, announced the Zero Carbon Bill, and headed to Paris to co-chair a meeting of heads of state and tech companies to curb violent extremism content from online platforms.

Last week the Government released its Wellbeing Budget, but it shared headlines with the controversy that National staffers had been able to access confidential Budget information ahead of Budget day by using the Treasury website's search bar.

The centrepiece of the Budget was $1.9 billion into the mental health and addiction treatment sector, but there was also $1 billion for KiwiRail, $320