Barnett says he would accept 70c GST floor

West Australian Premier Colin Barnett has called on the federal government to pick a figure for the proposed GST "floor", saying he would agree to 70 cents in the dollar as the prime minister has indicated.

Malcolm Turnbull told the Liberal state conference in August a floor would be set below which no state or territory's share of the tax could fall, responding to WA's complaints its slice had fallen to a record low of 30 cents.

Mr Turnbull was immediately pressed on the issue when speaking with reporters in Perth on Monday - his first visit west in six months - and only repeated consensus needed to be reached between all jurisdictions.

A floor would be set once WA's share recovered, he added.

Mr Barnett would not be drawn on whether he was disappointed by the vague commitment, but said he took some comfort that the prime minister referred to 70 cents.

"He didn't say that was the floor but he nominated it as a potential figure," the premier said on Tuesday.

"What I'm looking for is for the floor to be nominated ... 70 cents, I'd accept that."

Mr Barnett disagreed with the assertion that an agreement between all states and territories was an impossible dream.

He said he had for some time advocated quarantining about $10 billion of the roughly $60 billion a year the commonwealth collects in GST to propping up the weaker states, with the remainder allocated on a population basis, and that proposal could pass muster.

"That's why the leadership must come from Canberra," he said.

"It is a waste of time talking about tax reform, raising the GST - anything else - unless the commonwealth government addresses this issue."

GST distribution to the states was "a rubbish system that has outlived its life", Mr Barnett said.