PRIME Minister Scott Morrison is promising to legislate changes to GST distributions within weeks to guarantee Western Australia’s share does not fall below 75 cents in the dollar.

Mr Morrison is making the pledge to kick off a three-day visit to WA, matching a recent commitment made by Opposition Leader Bill Shorten to enshrine the GST floor in law.

“The legislation implements the Government’s decision for a new, fairer GST deal,” the Prime Minister told The West Australian.

“It prevents the system becoming a political football, not just between the major parties, but in the argy-bargy and games often played between the states, territories and the Commonwealth.”

In August, Mr Shorten promised to legislate the GST floor within 100 days should Labor be elected. Now the Morrison Government plans to do it during the next parliamentary sitting.

Treasurer Josh Frydenberg said it was clearly unsustainable for WA to be getting just 30 cents in the GST dollar.

“So what we are going to do is to legislate a floor of 75 cents in the dollar for any state or territory,” he told Today.

“We are providing an additional $9 billion and … every state and territory will be better off as a result of our reforms.”

Mr Frydenberg said it was now up to Labor to support the legislation.

“Bill Shorten, just a few weeks ago, was in WA saying he wants to support us in legislating it. So let’s just now see if he walks the talk,” he said.