Eric Ripper's future in the Western Australian Labor Party remains on shaky ground as more members speak out against his leadership.
Speculation is growing that the opposition leader will be forced to resign this week to avoid a leadership spill after losing the support of several MPs.
A recent Newspoll showed WA Labor's vote on a two-party preferred basis was down to 41 per cent.
Mr Ripper's personal approval rating dropped to 18 points, while Premier Colin Barnett's gained three points to 59 per cent.
It is understood Mr Ripper has lost the support of seven MPs aligned to the party's left and is unlikely to have the 19 votes needed to remain the leader if there is a challenge.
Several MPs have spoken out against Mr Ripper's leadership in recent days. The latest was the member for Bassendean, Martin Whitely, who also announced he would quit politics at the next election.
Mr Whitely told AAP that members were losing faith in Mr Ripper's abilities as a leader.
"Labor will not have a political future if we don't change now," he said.
"Eric has done the best that he can, but we're going backwards.
"Not only would we lose the election in 2013, but it would also make it difficult to win 2017."
Mark McGowan, Peter Tinley and Ben Wyatt, who made an unsuccessful challenge against Mr Ripper last year, have all been touted as potential leaders.
Mr McGowan has been in parliament since 1996, has ministerial experience and was a high-profile shadow minister.
He declined to make a comment to AAP about the leadership situation.
Mr Tinley, the member for Willagee, entered parliament in a by-election in 2009.
But he has ruled himself out of challenging for the leadership and nominating for the job if a spill is called.
Mr Wyatt entered parliament in 2006, winning the seat of Victoria Park after then leader Geoff Gallop resigned, citing depression.
He remained on the front bench after his failed challenge but lost the shadow treasury portfolio.
The member for Cockburn, Fran Logan, told AAP he supported Mr McGowan.
"He's good with detail and a good strategist, so I think he's the best person for the job," he said.
Mr Logan said he did not have a problem with the way some politicians had spoken out against Mr Ripper, adding it was just part of the political process.
Mr Ripper has been on leave since the end of last week, but before he left he said that he would remain Labor leader as long as he had the support of the caucus.
Deputy leader Roger Cook told AAP he had not spoken with Mr Ripper since he went on leave.
Mr Cook said communication between other members of the party was ongoing.
"As a senior member, people speak to me, they share their views, but I won't say what those views are," he said.
"People are trying to work out what is the best for the party to be a good opposition and a competitor for the election."
Mr Cook said it was "regrettable" that the situation was being played out in public.
"It would be best to be resolved internally," he said.
