Labour has sunk below National in the latest 1News/Colmar Brunton poll, 43 per cent to 44 per cent.

It is the first poll since Simon Bridges took over the National Party leadership in February.

But Labour's partners in Government, New Zealand First and the Green, are both on five per cent and the three parties combined would translate to 66 seats in the House, comfortably ahead of National and Act with 55 seats.

Labour has sunk by five points, but its last poll at 48 per cent seemed was unusually high.

Popularity for Prime Minister Jacinda Ardern has also fallen. Ardern's popularity is now at 37 per cent, down 4. While National party leader Simon Bridges has seen a surge in popularity from 1 per cent to 10 per cent.