SYDNEY (Reuters) - Australian Prime Minister Malcolm Turnbull and maverick nationalist politician Pauline Hanson faced questions about their leadership on Monday after their parties suffered a resounding defeat in a state election at the weekend.

FILE PHOTO - Australia's Prime Minister Malcolm Turnbull looks at his phone during House of Representatives Question Time in Parliament House, Canberra, Australia, November 9, 2016. AAP/Lukas Coch/via REUTERS/File Photo

Turnbull had already been trying to fight back against plummeting opinion poll numbers and leadership dissent within his center-right Liberals, the senior party in the ruling Liberal-National coalition, before the opposition Labor party scored a landslide win in the Western Australia state election.

Support for Turnbull is at its lowest since he grabbed power in a party-room coup in September 2015 and party disharmony has been magnified as voters abandon the mainstream amid a resurgence among far-right parties such as One Nation.

Yet, in what appeared to be a political own goal, both the Liberals and Hanson’s One Nation suffered after their Western Australia state branches agreed to share preference votes under Australia’s complicated preferential voting system.

The vote had been seen as the first major test of popularity for Hanson since winning a place in the federal parliament last year, when she rode a wave of anti-establishment sentiment similar to that seen in the United States and Europe.

However, Hanson’s party appeared set to win only two or three seats, well short of predictions it would win enough to influence legislation.

Hanson said her party had been dragged down by the Liberals.

“People were supportive and said they wanted to vote for us but said when they heard we were doing preference deals ... they could not vote for us,” she told Channel 7’s Sunrise program.

The road ahead is no easier for Turnbull, whose party faces another stiff state election test in northern Queensland within the next 12 months.

“There is some talk he won’t last the next few months but, should he lose the (Queensland) election this year, I can’t see him making it through 2017 as leader,” said Haydon Manning, a political scientist at Flinders University.

Underscoring the internal dissent, Nationals leader and Deputy Prime Minister Barnaby Joyce broke ranks and suggested the decision to ditch traditional conservative allies and swap preferences with One Nation had indeed been a factor in the defeat, leaving voters unsure who they were voting for.

Opposition Labor leader Bill Shorten jumped on the division to highlight the significance of the preference deal, under which preferences from losing candidates are redistributed among larger parties according to how candidates are ranked on ballot papers.

“A vote for One Nation was a vote for the Liberal party,” Shorten told reporters in Melbourne.