ACC Minister Judith Collins has finally rejected a return to "pay-as-you-go" funding for the state-owned insurer, after earlier refusing to rule it out as part of a review of funding options.

"Pay as you go is not for us, no," she said today.

Labour spokesman Andrew Little has called for a debate about dumping the current fully funded model, which would allow levies to drop by up to 25 per cent.

The Greens' Kevin Hague favoured a switch to pay-as-you-go, but was also eyeing up to $15 billion in reserves held by the corporation for other projects.

Collins said the Government did not want to burden future generations with the cost of current accidents.

"I'm surprised that the Greens and Labour, who support the Cullen fund on the same basis as it's pre-funding superannuation, would suddenly decide that they want to burden our future generations with the cost of our injuries."

Some claimants could be with the corporation for up to 80 years, so it was unrealistic. to shift to pay-as-you-go.

She said the corporation was doing well on funding.

"What we're looking at is just looking at some of the levels of pre-funding," she said.

Under the current fully-funded model, ACC sets levies to cover the current and future costs of existing claimants and is aiming to reach its fully funded target by 2019. ACC currently has investments of $19.5b and a net liability of $4.5b

Hague had said changing the way ACC was funded could give a $1b windfall to workers and businesses and free up the reserves to cut government debt or fund the Christchurch rebuild.

Little favoured leaving the existing reserves with ACC.

In the current year, ACC expects to collect $5b in levies from workers, employers and motor vehicle owners and pay out $2.8b.

- © Fairfax NZ News