Former Opposition leader Mark Latham is tossing up a return to politics, but it's not clear which party would make the best fit for the one-time Labor leader who has since been exiled from the party.

Key points: Mark Latham appeared with One Nation leader Pauline Hanson on TV last night but said he was still undecided on whether to join her party

Mark Latham appeared with One Nation leader Pauline Hanson on TV last night but said he was still undecided on whether to join her party He joined David Leyonhjelm's Liberal Democratic party last year

He joined David Leyonhjelm's Liberal Democratic party last year The Labor Party has declared it will never take its former leader back, labelling him "a rat" and a "distraction"

Mr Latham appeared with One Nation leader Pauline Hanson on Sky News last night, but said he was still undecided on whether he would join her party.

"I've not made any decision — I do get people urging me, mainly on the basis, they say, that the country's gone crazy," he said.

"When you look at the political correctness, the identity politics, the anti-white racism.

"People so often say to me 'the country's gone mad. What's happened? Why has it changed so badly in the last decade. You should get in and do something'."

Senator Hanson said she would love to have him beside her in Parliament.

"Mark knows that I'd be quite happy to have him on board, but Mark's his own person," she said.

"Whether he wants to get involved in politics again, that's up to Mark."

Mr Latham has voiced a pre-recorded robocall message for One Nation ahead of the upcoming byelection in Longman, north of Brisbane.

In that message, he warns voters not to trust his former party — a move which came as a surprise to Liberal Democrats Senator David Leyonhjelm.

Mr Latham joined Senator Leyonhjelm's party last year.

Mark Latham pursued Julia Gillard during the 2010 election campaign, as pictured here at the Brisbane Ekka. ( AAP: Gary Ramage )

And Senator Leyonhjelm said he had also been in discussions with Mr Latham about a possible comeback over recent weeks.

"He still has to take into account the views of his wife, his kids and whether he actually wants to return to politics," Senator Leyonhjelm said.

"Going back into politics for the second time is a bit like getting married a second time.

"It's a triumph of hope over experience."

No chance Labor would take Latham back

Mr Latham led Labor's unsuccessful election campaign against John Howard in 2004, quit politics the year after and swore he'd had enough of public life.

For its part, the Labor party has already declared it will never take Mr Latham back. It made that announcement after he joined the Liberal Democrats.

Opposition Leader Bill Shorten dismissed Mr Latham's robocalls as a "sideshow" and a "distraction" from the issues at the heart of upcoming by-elections, and Shadow Treasurer Chris Bowen labelled Mr Latham "a rat".

"I think the Australian people would see through the charlatan that he is, that he's become," Mr Bowen said.

"I say that with no relish. It's sad to see a former Labor Party leader sink to depths.

"But he'll go down as one of the great Labor rats of history."

Mark Latham led Labor's unsuccessful election campaign against John Howard in 2004. ( AAP: Mick Tsikas )

ALP President Wayne Swan said the idea of Mr Latham making a political return at all was extraordinary.

"He's been in just about every political party in the history of this country," Mr Swan said.

"So what we'll see from Mark Latham and what we'll see from Pauline Hanson is more of the same — which is kooky extremism."

In a heated exchange on Sky News last night, former Labor politician Graham Richardson told Mr Latham the party's forefathers would be "rolling in their graves" if they knew what he was up to.

Sorry, this video has expired Graham Richardson says Labor forefathers are 'rolling in their graves'

Latham interested in rallying minor parties

Mr Latham told Sky News he now liked the idea of getting several minor parties to band together.

He said that would strengthen democracy by giving them enough clout to properly challenge the Liberals and the ALP.

"Because they're not doing the job," he said.

"They've lost heaps of support and I'm absolutely convinced that the people are crying out to make Australian politics more competitive."

Senator Leyonhjelm said he liked that principle, but finding enough common ground to amalgamate with groups like Australian Conservatives or One Nation would be difficult.

"What would it stand for?" he said.

"The Liberal Democrats, for example, support low taxes.

"One Nation supports low taxes for individuals, but has opposed the reductions in company tax.

"So there'd be some policy differences that I think would stand in the way of that."

Mr Swan scoffed at Mr Latham's plan for an amalgamation of minor parties. He said both One Nation and Mr Latham would just support Coalition policies anyway.

Mr Shorten said any vote for One Nation in the upcoming by-elections would effectively be "a vote for Malcolm Turnbull's tax cuts for the big banks".