WA Premier Mark McGowan says he will likely agree to the Commonwealth's hospital funding deal amid continued concerns about the state's share of GST revenue.
Other Labor premiers remain sceptical of the scheme, but Mr McGowan says WA needs the funding certainty.
"We're more likely to sign it than not ... I understand others aren't," he told reporters in Canberra at the Council of Australian Governments meeting.
Under the deal, the Commonwealth will continue to pay 45 per cent of hospital funding but cap annual growth in federal spending at 6.5 per cent.
Mr McGowan said states like South Australia could afford to oppose the deal with their share of the GST.
"I heard the South Australian premier this morning complain about other states taking their water while they're willing to take rivers of Western Australia's GST," he said on Friday.
He said although it was not on the COAG agenda, everything relates to the GST.
"Its been very unfair on Western Australia for a very long time and states like South Australia ought to realise they've been so successful getting GST for defence spend, they need to give something back."
