The Liberal Party of Western Australia (WA) has been voted out of government in a landmark result for the state's Australian Labor Party (ALP).

The new Labor government, led by Premier-elect Mark McGowan, is expected to pick up as many as 41 of the 59 seats in the lower house of WA parliament.

The election marks the end of eight and a half years in Opposition for the ALP in WA, traditionally one of Australia's most conservative states.

Among the casualties for the Liberals in the 16 percent swing against the party were at least four government ministers with two others also facing the possibility of losing their seat.

McGowan used his victory speech to push home his key election promises, most notably a multi-billion-dollar public transport system for the state.

"With success comes responsibility and the obligation to implement our program," McGowan told his jubilant supporters.

"We will get to work immediately on carrying out our plans."

"You deserve good government and, with my team, I am committed to delivering just that," McGowan said.

Though McGowan will have unconditional control on the lower house, his party's hold on the WA Senate will be much more tenuous with minor parties winning as many as five seats.

Outgoing Premier Colin Barnett, who faced a leadership challenge in September of 2016 as signs were ominous for the election, said he did all he could to retain government for the party.

"My best shot wasn't good enough, but I can assure you I gave it my best shot," Barnett said.

"I pledged to be a pro-development government and a government of integrity.. and we have."

"The over-riding factor was time. The voters only give a government a certain amount of time. It's a trend," Barnett added.

The results have been described as disastrous for the far-right wing One Nation Party (ONP) which, despite winning two seats in the Senate, received just 4.5 percent of the vote in the lower house and won no seats.

source: Xinhua