Kim Beazley, former Labor leader and ambassador to the US, says Pauline Hanson's One Nation is a threat to Australia's national security and prosperity.

Mr Beazley has told Lateline the Liberal Party was "utterly unprincipled" for making a preference deal with One Nation in the upcoming West Australian election.

He said it was time to get sensible about the party, which took its first turn on the political stage when he was Labor leader.

"The positions that they're adopting threaten our security and our prosperity," he said.

"We absolutely need to be global open traders. How do we sell our minerals if people are erecting tariff barriers against them? How do we get in to supply chains?

"And then you get round to the issues here. We keep debating tolerance all the time — look at the neighbourhood in which we live.

"We sit here alongside the biggest Muslim nation in the world, utterly dependent on close relations with them to control immigration, and to control our defences.

"Why do you want to go round kicking them up the backside?"

Mr Beazley said the WA preference deal was "desperate".

"It's an extraordinary thing to do: To diss your National Party colleagues, to probably force a few of them out of Parliament and replace them with One Nation people," he said.

Some One Nation candidates in WA have threatened to disobey their own party over the controversial preference deal.

However Pauline Hanson says if they are not happy, they can quit the party and run as independents.

Meanwhile, Mr Beazley, who finished his term as US ambassador last year, described Donald Trump's presidency as "as bad as it gets, and it's not over yet".

"It obviously has to get better. I suspect it couldn't get worse."