Labour may have distanced itself from the union movement, but unions remain its largest source of donations.

Electoral returns compiled by Newstalk ZB show ten-percent of Labour's declared donations since the start of 2012 have come from unions.

Nearly two thirds of that came from E tu, and its predeccessors, the Service and Food Workers Union and the EPMU.

Labour also received major donations from transport and farming unions, making it the only party to receive any substantial union support.

The party raised $3.3 million during the period, less than half the $8.2 million raised by National over the same period.

 

National's contributions came from a range of sources, including several major contributors.

Christchurch's Cyril Smith contributed $580,000, and Hamilton's Gallagher Group and family and Auckland real estate director Garth Barfoot also made major contributions.

The figures show Kim Dotcom, Colin Craig and Gareth Morgan have also entirely bankrolled their parties.

More than half of the ACT Party money came from Dame Jenny Gibbs and Alan Gibbs, and more than a third of the Maori Party's donations came from Mainfreight founder Bruce Plested.

The Greens received nearly $2.5 million in donations during the period, but most of that came from its own MPs.

The figures include all donations in the party's annual returns from 2012 to 2016, and its declared donations over $25,000 from January to July this year.