West Australian Premier Colin Barnett says he's received clarification of the federal coalition's paid parental leave plan and the state will co-operate with it.
The Liberal leader told reporters in Perth on Monday that the scheme was overly generous.
While WA would assist with its administration, he said, it would not help to pay for it.
The federal government pounced on the comment, asking if Queensland Premier Campbell Newman, NSW Premier Barry O'Farrell and NT Chief Minister Adam Giles agreed with Mr Barnett that the "Rolls Royce scheme" was "a rolled gold dud".
The scheme would largely be paid for by a levy on big business.
On Tuesday, a WA government spokeswoman confirmed the federal coalition had provided clarification of details of the scheme overnight.
"We understand that under the scheme, the coalition would fund the gap between the current state schemes and the coalition's 26-week scheme, and the WA government would co-operate," she said.
"The WA government wouldn't directly pay funds into a Commonwealth scheme."
NSW Premier Barry O'Farrell later said he supported the plan.
"It is very good news for working mothers," Mr O'Farrell said in a statement.
"I look forward to working with (Mr Abbott) on its implementation if he's elected."
