The Labour Party is struggling to put a dent in National's substantial lead in the opinion polls, just four months from the general election.
In the latest One News Colmar Brunton poll, the National Party recorded 53% support. Labour has fallen further behind, registering just 27% support.
The Green Party's support jumped to 10%, while support for the Maori Party doubled to 3%.
Support for ACT and New Zealand First also rose marginally but both remain well below the 5% party vote threshold.
The Labour leader Phil Goff told Morning Report he's not reading much into an opinion poll, as polls go up and down.
He says he's confident Labour's policies will attract low and middle income earners to the party.
The poll of 1008 voters conducted between 9 and 13 July has a margin of error of plus or minus 3.1%.