The former leader of the Labor Party, Mark Latham, has joined One Nation and will run for the NSW Parliament.

Key points: Mark Latham will run for NSW Parliament and lead the state branch of One Nation

Mark Latham will run for NSW Parliament and lead the state branch of One Nation He says immigration, congestion, over-development and power prices will feature in his campaign

He says immigration, congestion, over-development and power prices will feature in his campaign ABC elections analyst Antony Green believes Mr Latham will be elected in the upper house

Speaking on Alan Jones' 2GB radio program this morning with One Nation leader Pauline Hanson, Mr Latham said he was putting his hand up because he believed NSW voters needed a third choice.

He identified immigration, congestion, over-development and electricity prices as some of the issues he would use to campaign.

But Mr Latham also hit out against "political correctness" and "divisive identity politics".

"These are all issues that are banking up in NSW they haven't been addressed by the major parties," he said.

"I want to provide people with a third choice — to say you can vote One Nation and have practical, commonsense solutions to these big issues in our state."

Mr Latham had been teasing a political comeback of sorts for months, telling news outlets he has been asked by four parties to consider a Senate run.

However, he previously refused to say whether he would accept any of the offers from parties he would not name.

During the Longman by-election, Mr Latham recorded robocalls for One Nation urging people to vote against the major parties.

Senator Hanson said she was proud to have Mr Latham on her team.

Former prime minister Julia Gillard and former Labor leader Mark Latham in a now famous meeting on the campaign trail in Brisbane in 2010. ( Gary Ramage: AAP )

"These major political parties here won't have their own way, we will make them work for the people of this state," she said.

"We need ideas that are driven by good policies and to get the state moving."

Mr Latham said he was at a stage in his life where he was unable to "stand on the sideline".

"This is a fight for our civilisational values, for free speech, for merit selection, resilience, love of country, all of it under siege from the left," he said.

Labor leader Luke Foley ruled out any preference deals with One Nation following Mr Latham's announcement.

"We will not preference One Nation candidates anywhere in NSW," he posted to Twitter.

"I challenge the Liberals and the Nationals to make the same commitment."

John Howard and Mark Latham shake hands on election eve in 2004. ( AAP: Mick Tsikas )

A complicated political history

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.

However he returned in 2010, following former prime minister Julia Gillard on the campaign trial as an employee of the Nine Network.

He worked as a columnist for the Australian Financial Review until he left in 2015 following a series of tweets criticising a range of journalists.

Last year, Mr Latham was sacked from Sky News as host of the Outsiders program after a series of controversial remarks.

What are his chances?

ABC elections analyst Antony Green was confident Mr Latham would be elected because the quota in the NSW upper house was four-and-a-half per cent.

"Realistically, get two-and-a-half per cent and you'll get elected. I imagine One Nation will easily reach that level," he said.

Mr Latham will be competing against the Shooters, Fishers and Farmers Party and Christian Democrats in trying to add another right-of-centre option to the balance of power, Mr Green added.

One Nation has previously polled well in country NSW, as has the Shooters, Fishers and Farmers Party.

"There will be a problem that One Nation and the Shooters, Fishers and Farmers might split the right-of-centre vote in competition with the National Party," Mr Green said.

"That creates a problem under optional preferential voting used in NSW."

One Nation had no chance of being elected in the lower house, he said.