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 or above 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.
Support for Prime Minister Jacinda Ardern as preferred Prime Minister is down by four points to 37 per cent but she is well ahead of the 10 per cent for Bridges, who replaced former Prime Minister Bill English in February.