Act and the Maori Party were under 2 per cent.
RNZ's poll of polls takes the average of polls from 1 News Colmar Brunton, Newshub Reid Research and UMR Research polls.
Labour leader Jacinda Ardern's popularity remained high in the UMR Research poll, down three points to 76 per cent favourable rating.
National leader Simon Bridges, who languished in low figures in recent 1 News Colmar Brunton and Newshub Reid Research polls, went from 36 per cent favourability in March to 45 per cent in May.
The UMR Research poll found most people still believed the country was on the right track, down six points from February to 63 per cent positive.