The PM has dismissed PUP’s traction as “novelty value” and says it’s “a personality cult for one person”.

Prime Minister Tony Abbott has taken another swipe at Clive Palmer, dismissing his political outfit as “a personality cult for one person”.

Mr Abbott has repeatedly accused Mr Palmer of trying to buy seats in parliament in a bid to further his own interests.

And on Wednesday, he asked what it meant for democracy when candidates were “a proxy for a minor party that is a personality cult for one person”.

“It’s something for voters to ponder in the lead-up to Saturday,” he told ABC radio in Perth on Wednesday during the West Australian Senate election campaign.

On the party’s appeal, Mr Abbott said: “I think there is a certain novelty value and obviously there has been a massive, massive, massive advertising spend.

“So far, the gentleman in question has spent – presumably from his own money – far more than the combined spending from both the Liberal Party and the Labor Party,” he said.

But Labor deputy leader Tanya Plibersek, also campaigning in Perth on Wednesday, said it was up to each party to determine how much was spent on a campaign.

“We believe in a democracy,” Ms Plibersek said.

“As long as a political party declares all its donations, as long as it abides by the rules, they’ve got every right to spend the money they raise.”

Despite the Greens being the second biggest spenders in the re-run WA Senate election, leader Christine Milne said the party wanted to see expenditure on campaign ads capped in light of the Palmer United Party ad blitz.

“This is the first time in Australian politics where we’ve had a rich individual being able to so manifestly influence the vote,” she said.

Greens Senator Scott Ludlam said his party’s ad spending was different to PUP’s because the funds came from a large amount of small donations.

Mr Palmer said PUP’s advertising cash splash was his personal money to do with what he wished.

He said he had only spent a third of what the Liberal Party did at the 2013 federal election.

“No matter how much money you spend on advertising, if you have a bad idea people won’t vote for you,” Mr Palmer told Network Ten.

If PUP wins a WA Senate seat on Saturday, it will have three members on the upper house crossbench after July 1.