I have not broken GST promise with WA: PM

Malcolm Turnbull has rejected reports he has broken a promise to Western Australians by not setting a floor on the share of GST a state could receive or that he had never raised the matter with other premiers.

"Those statements are untrue," the prime minister said in a statement on Tuesday, coming in the wash-up of the Liberals' hefty loss in last weekend's WA election.

Mr Turnbull said he told the 2016 WA Liberal Party State Council with WA's GST share set to more than double in the next few years it would then be an opportunity to set a floor and he subsequently wrote to the premiers and chief ministers and the matter was discussed at the Council of Australian Governments.