WA Premier Colin Barnett is maintaining his staunch defence of the Liberals preference deal with One Nation, while distancing himself from extreme comments of some of its candidates.

A series of offensive tweets sent by South Metropolitan One Nation candidate Richard Eldridge in 2013, including derogatory descriptions of Muslims, gay and lesbian people and other minority groups, were detailed in a newspaper report today.

In response, Mr Eldridge posted on Facebook that coverage of the remarks was a "vicious attack" on him by the "grubby left-wing media".

However, the post was taken down after it attracted a series of comments condemning his defence of the tweets.

Mr Barnett said Mr Eldridge's tweets were "abhorrent".

He said he was neither interested nor supported the policies of One Nation and did not believe he would be judged harshly for the preference swap.

"I'm not keeping company with One Nation. I have never met Pauline Hanson. I have never spoken to her. And I probably don't think I will ever end up doing so," he said.

The Premier and other senior Liberals have repeatedly characterised One Nation as a different party to when Pauline Hanson first emerged 20 years ago.

But a steady flow of extreme comments linked to some One Nation candidates has seen the Premier repeatedly challenged over the preference deal.

Mr Barnett shrugged off questions about the morality of agreeing to swap preferences with a party opposed to immigration, and advocating a ban on burkas.

He said questions about One Nation candidates should be directed to One Nation.

Mr Barnett says questions about One Nation should be directed to that party. ( ABC News: Andrew O'Connor )

"I don't know how the party works. I'm not particularly interested in the One Nation party so if you've got any questions about their policies or how they pick their candidates or where they come from, you have to direct it to Pauline Hanson," he said.

"I'm not a spokesperson for One Nation. I'm just not going down that path.

"Look around, you get lots of odd people in politics, across all parties from time to time. Nothing unusual about that. [It's the] nature of democracy."

Labor leader Mark McGowan described the comments as "completely and utterly unacceptable", again taking aim at the Liberals for striking a preference deal with One Nation.

But, asked if One Nation had become more moderate in the past 15 years as Mr Barnett has claimed, Mr McGowan would not be drawn.

"I'll let other people make those judgement calls for themselves," he said.

"But we are putting One Nation last and we are standing on our own two feet."