The Green Party is splashing the cash paying people to collect signatures for a petition to force a referendum on government plans to sell down the Crown's stake in a number of assets.

The Greens will spend $50,000 on paying the equivalent of 10 fulltime staff for the next six to eight weeks to collect signatures for a citizens-initiated referendum on asset sales, the Dominion Post reports.

The Greens also have about 2000 volunteers helping with the campaign.

The bid for a citizens-initiated referendum is supported by a coalition of Grey Power, the Council of Trade Unions, Greenpeace, the Union of Student Associations, Labour and the Greens.

At least 310,000 signatures, 10 per cent of the voting population, are needed to force the government to hold a non-binding referendum.

Labour has 1500 volunteers collecting signatures but is not hiring any staff.

Funding to pay for the staff was coming from the Greens' $1.3 million annual leader's fund, co-leader Russel Norman said.

Shares in the first asset to be partially privatised, Mighty River Power, are due to be put on the market sometime after July.