12/03/2017 9:38 AM AEDT | Updated 12/03/2017 11:58 AM AEDT

Government Says Shocking WA Election Result Was 'A Long Time Coming'

The WA Liberals were thumped in the state election.

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Minister for Finance Mathias Cormann says the poor result for the Liberals at the WA election was expected.

The federal government has downplayed the catastrophic WA election result, describing the landslide Liberal-National loss as "a long time coming".

WA Premier Colin Barnett was routed at Saturday's state election after eight-and-a-half years in office, with Labor predicted to pick up 41 seats.

Speaking on Sunday, Finance Minister Mathias Cormann said the result was not a surprise.

"The election result last night has been a long time coming. It is not unexpected. All of the published and internal polling indicated that this was the way it was going to go," Cormann told ABC television.

"As far as the preference deal is concerned, the Liberal Party's consideration was looking at our primary vote long before the campaign got underway, long before any preference arrangements were entered into."

Prime Minister Malcolm Turnbull congratulated Labor leader Mark McGowan on the win and commended Barnett for his management of the state.

Turnbull described Barnett as a "powerful advocate" for the interests of Western Australia over the past eight years.

"I congratulate Mark McGowan on his victory in the Western Australian state election yesterday and I thank Colin Barnett for his outstanding leadership over more than eight years," he said in a statement.

"Colin became Premier when the State was in the midst of the global financial crisis and he has since managed the State during the largest resources boom in our history and its inevitable wind down.

"The State's remarkable progress is due in large part to the leadership of Colin Barnett."

Opposition Leader Bill Shorten said Turnbull's refusal to stop cuts to penalty rates and contributed to Labor's strong performance.

Shorten also said the WA Liberals were hurt by their preference deal with One Nation.

"I think today Mr Turnbull should say that he's heard the lessons of Western Australia. He should rule out once and for all doing any further deals with One Nation," Shorten told reporters in Melbourne.