Labour and the Green Party have received a small boost in a One News Colmar Brunton poll taken over the period in which the parties announced an agreement to work together.
National is still riding high on 48 per cent - but did not receive any increase in support following last month's Budget.
The poll has put National on 48 per cent (down 2 per cent), Labour on 29 per cent (up 1 per cent), the Greens on 12 per cent (up 2 per cent) and New Zealand First unchanged on 9 per cent.
The poll of just over 1500 eligible voters was taken between May 28 and June 2 and has a margin of error of plus or minus 2.5 per cent.
Labour leader Andrew Little and Green co-leaders James Shaw and Metiria Turei announced on May 31 that they had signed a Memorandum of Understanding.