Federal Labor would risk losing “every seat in WA” if it reneged on the GST deal, Treasurer Rita Saffioti believes. Speaking to a CCI breakfast amid fresh calls from East Coast economists to axe the deal, Ms Saffioti said there was no way any Federal government would change the deal, and had confidence Prime Minister Anthony Albanese would uphold it. The West Australian reported on Tuesday calls from Liberal Leader Libby Mettam for the State Government to get written confirmation from the Prime Minister of the deal’s security. “There’s no way they’ll change that deal for Western Australia,” Ms Saffioti said. “I don’t think any government will, to be honest, politically it just would not work. “So they would basically, I think, lose every seat in Western Australia. So there’s just no way. “In relation to the productivity commission review, we will continue to work to better prove our case in relation to the formula itself.” The comments came after Eastern States media reported the cost of the deal was projected to increase to $50 billion, with calls for the Productivity Commission to axe it. Economist Saul Eslake accused the Federal Government of maintaining the deal to achieve a “crude political calculation” of keeping seats in WA. “That represents a transfer of almost $40 billion from the Federal Budget to the WA State Government, the only government in Australia and one of very few in the world which is running and expects for the foreseeable future to run persistent budget surpluses, so that they can run even bigger ones,” Mr Eslake said in a paper on the topic. Ms Saffioti said without the deal, WA would be receiving just 8¢ in the dollar. “That is not sustainable. We’ll continue to fight to make sure it’s protected,” she told reporters after the CCI event. “No one would believe that Western Australians deserved only 8 per cent of their population share. That’s not a sustainable argument economically. “And the other point is that Western Australians can contribute billions of dollars to the national bottom line. “It’s very frustrating in particular when these so-called economic experts make these comments because they’re not looking at the full economic case.” Ms Mettam urged the State Government to secure the deal in writing from Prime Minister Anthony Albanese, something Ms Saffioti said had already been done. At a separate event, Premier Roger Cook said there had never been an indication that the Government would not stick to the GST deal. “In the back end of last year, we had a national Cabinet meeting where these issues were discussed, including the no worse-off guarantee and the Prime Minister committed to the current arrangements for another three years,” Mr Cook said. “I can also confirm that just earlier this month, the Prime Minister wrote to me confirming the decision of National Cabinet and reiterating his support for the current arrangement.” Treasurer Jim Chalmers said Labor was sticking with the arrangements that give WA a fair share of the GST. “This isn’t a genuine question from the WA Liberals, it’s a search for relevance,” the Treasurer said. The deal remains important for the Federal Government’s political survival, winning in 2022 after picking up the WA seats of Swan, Pearce, Hasluck and Tangney from the Liberals.