A "secret" report on the NSW child protection system must be released by the state government within days, according to the Greens.
The government lost a vote in the NSW upper house on Thursday, meaning it will have to produce the Tune review within four calendar days.
Greens MP David Shoebridge says the report is understood to have recommended an overhaul of the out-of-home care system.
"This government is getting a lesson in accountability losing yet another vote in the upper house that will now force it to release a crucial child protection report that it has been desperate to keep hidden," Mr Shoebridge said in a statement.
A spokesman for Family and Corrective Services Minister Pru Goward said the government would consider the standing order and would respond by the due date.