The commonwealth should cough-up an initial contribution of $250 million for a national redress scheme for child abuse survivors, the Greens say.

And that amount should be matched by the states and territories.

The minor party is prepared to work with whoever forms government after the July 2 election to get a redress scheme in place as soon as possible, West Australian Greens senator Rachel Siewert told reporters in Canberra on Monday.

"Survivors have suffered long enough; it's time that action is taken," she said.

Australia had a responsibility to look after all its children which is why it was so essential the commonwealth show leadership.

NSW state Greens MP David Shoebridge hopes the federal election commitment would "flush out" the coalition.

The federal government announced in January it would lead states and territories in developing "a nationally consistent approach to redress".

Senator Siewert said such an approach risked having a different scheme in each jurisdiction.

The royal commission into institutional responses to child sexual abuse recommended a national scheme, which it estimated would cost $4.3 billion over 10 years and be underwritten by the federal government.

The Greens plan, costed by the Parliamentary Budget Office, would set up a national, last-resort scheme funded 50-50 by the commonwealth and states and territories to pay compensation where institutions no longer existed or didn't have enough money.

Payments would range from $10,000 to $200,000 and the scheme would also fund counselling.

It would cost the federal government $250.5 million over the next four years and up to $1 billion over a decade.