Just 31 votes are keeping the decimated West Australian Liberals alive in their battle to claim a third lower house seat.
The count is continuing after Labor's landslide election victory, with Sean L'Estrange clinging on by the tightest of margins in his previously-safe seat of Churchlands.
About 76 per cent of the count has been completed and the trend favours Labor candidate Christine Tonkin.
Labor has claimed victory in former Nationals leader Terry Redman's southwest seat of Warren-Blackwood for the first time since its establishment in 1996.
The latest preference count on Wednesday left Labor's Jane Kelsbie more than 500 votes ahead.
Labor also remained ahead in the blue-ribbon Liberal seat of Nedlands, setting the party up to potentially claim 53 out of 59 lower house seats.
The Nationals would hold four seats and the Liberals just two under that scenario.
Labor is now certain to win control of both houses and the Nationals are likely to take over opposition status from the Liberals.
Premier Mark McGowan on Wednesday unveiled his new-look cabinet, promising Labor would use its vast majority to govern in the interests of all voters.
Amber-Jade Sanderson, Don Punch, Reece Whitby, Tony Buti and John Carey have been promoted, while Michelle Roberts will become the first female speaker of the lower house.
Peter Tinley has been dumped from his housing and fisheries portfolios.
Mr McGowan will reveal the allocation of portfolios on Thursday, including who will replace the retired Ben Wyatt as treasurer.
The premier has not ruled out taking on the responsibility himself.
