West Australian Premier Colin Barnett has confirmed he asked Transport Minister Dean Nalder to take leave and not attend a regional Cabinet meeting in the Wheatbelt town of Moora.

Key points: Dean Nalder taking "a few days off", Colin Barnett says

Dean Nalder taking "a few days off", Colin Barnett says Premier denies initiating leadership poll witch-hunt

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In his first public comments since his crisis meeting with Mr Nalder on Friday, Mr Barnett also expressed his continuing concern about a privately funded opinion poll, bankrolled by high-profile business figures and widely seen as an attempt to elevate the Alfred Cove MP to the leadership.

The Barnett Government normally uses regional Cabinet meetings to showcase policies, programs and projects targeted at the region or sector.

As Transport Minister and Agriculture Minister, Mr Nalder was expected to be involved in a number of announcements to coincide with the Wheatbelt meeting.

However, Mr Barnett said in the wake of last week's events, he felt it best Mr Nalder stay at home.

"I thought it was a good idea that he didn't come to this Cabinet meeting and that indeed he took a few days off, so that's what we agreed to do," he said.

Dean Nalder has not spoken publicly since Friday's meeting with the Premier. ( ABC News: Andrew O'Connor )

"In that environment, I didn't think it was a good idea to have Dean taking part in these meetings in Moora. I didn't want it to distract from the Moora regional Cabinet meeting."

Mr Barnett called Friday's meeting with Mr Nalder to probe the Minister's knowledge of, and any involvement in, the private poll conducted by a group of business figures including investment banker John Poynton.

There had been speculation Mr Nalder would lose his Cabinet position, and Mr Barnett has confirmed that was the desire of some senior Cabinet members.

"Dean assured me that that was action [the businessmen] took and I accept what he had to say," he said.

"People were saying that Dean should be removed from Cabinet but I don't see it that way.

"I certainly acknowledge feelings were running high as to the involvement of business people conducting a survey. Accusations were made about Dean's involvement.

"It's my job as Premier to judge it as best I can and play it as straight as I can ... but I understand feelings running [high], not so much in Cabinet, more amongst the broader membership of the Liberal Party."

Collier backs Premier's Nalder ruling

Mr Barnett suggested Cabinet members would normally be sacked due to a clear transgression of the ministerial code of conduct.

Mr Barnett joined his Cabinet in Moora after asking Mr Nalder to take "a few days off". ( ABC News: Andrew O'Connor )

He said he saw no evidence of that in the actions of Mr Nalder or the account he provided in their private meeting.

Education Minister and senior Liberal powerbroker Peter Collier said Mr Barnett had his full confidence.

"I trust the Premier. I've got great confidence in the Premier's judgement," Mr Collier said.

Mr Barnett said he still wanted to know the identity of those involved in the private poll, but denied he had initiated any "witch-hunt" targeting Mr Poynton or property developer Nigel Satterley.

He said he remained concerned after the "turmoil" of last week about the attempt by private interests to interfere with the political process, and said the matter was still being scrutinised by the head of the Department of Premier and Cabinet and the Public Sector Commission.

"I think it's incumbent on any individual involved in that to come forward," he said.

"I expect their names will come out, sooner or later. But they might as well disclose it."

Barnett questioned over son's China trip

Mr Barnett was also asked about the latest controversy involving his son Sam, who was shown giving a property investment speech in China with a picture of his father projected on the screen behind him.

Sam Barnett speaks about property investment in China. ( Supplied: Seven News )

"It was a group of people basically going on a tour of China. They were property-related," he said.

"Sam had never been to China. He was asked to go along on the basis he would just give a few talks that he did.

"And Sam assures me that he wasn't aware that image was to be put up on the screen. He didn't do it, he didn't supply the image.

"Sam did not have any role in that image being put up. And let's face it: he is my son, he is what he is. And there's a photo of his son and his Dad."

Mr Barnett said while his son had made "some serious mistakes" over the last 12 months, he was not to blame in this instance.