West Australian Liberal MP Murray Cowper has joined fellow backbencher Helen Morton in condemning Premier Colin Barnett's continued leadership and have called for a change of direction for the party.

Mr Cowper, who is the Member for Murray-Wellington, told ABC South West Mr Barnett had lost his support during the Yarloop bushfires in January that claimed two lives and almost wiped out the town.

He said Mr Barnett had failed to show leadership during the fires and should be replaced, while Ms Morton said she would support an alternative premier if there was a spill motion at tomorrow's partyroom meeting.

Former transport minister Dean Nalder has said he would nominate for the leadership if a spill motion was passed.

Mr Nalder was one of two ministers to resign at the weekend, along with former local government minister Tony Simpson, who said he could no longer support Mr Barnett because of his "erratic and illogical" decisions.

Mr Cowper said he had made desperate attempts to contact the Premier to seek support on the night of the deadly fires, which destroyed more than 180 properties.

"I just think the way in which the whole thing happened.

"I can tell you that on the night of January the 7th I was contacting the Premier and others telling them that we could expect significant infrastructure loss because of the fires coming over the hill," Mr Cowper said.

"I didn't, couldn't get hold of the Premier, he didn't respond to my calls.

"He was up on holidays and I'm down here trying to support my people, so that was about the time he lost me."

Premier 'planted spies in my office': Cowper

He also accused Mr Barnett of planting "spies" in his ministerial office.

"I did have in my ministerial office ... spies from the toxic department of Premier and Cabinet spying on one's every move and obviously reporting back," Mr Murray said.

"You often wondered whether or not these people were working for you or they were working for the Premier."

Mr Cowper said people in his electorate of Murray Wellington were telling him they wanted Mr Barnett out of the leadership.

"I don't think we've done the job as well as we possibly could when it comes to the circumstances attending the fires earlier this year," Mr Cowper said.

"I suppose that's put us all under a lot of pressure but I think it's time for renewal based on the fact that I think we can do better.

"Clearly, we're bleeding out."

'Bullying culture in Premier's office': Morton

Ms Morton said her ministerial office had been affected by a "bullying" culture amongst the Premier's staff that had contributed to her losing her Cabinet post.

Ms Morton claims there is a bullying culture in the Premier's office. ( ABC News: Andrew O'Connor )

"It's just a situation now where that machine that surrounds the Premier is out of control," she said.

"The issue was really ... about a particular member of staff who I felt so strongly about was having such a demoralising and destructive impact across my staff that I banned that member of staff from having any further contact with me, my office or my staff."

She said polling suggested there needed to be a new Premier.

"Across the East Metropolitan region, they are telling us that they like what we've done as a government, they're pleased with us but it's time to change leaders and they're telling us they will not give Colin a third term," she said.

The Department of Premier and Cabinet has been contacted for comment.