Crossbench senator Nick Xenophon has announced he will be quitting federal politics and returning to state politics in South Australia.

He has told a press conference in Adelaide that next year's state election would be critically important, with South Australia at a crossroad.

Senator Xenophon said Labor and the Liberals in his home state were more interested in fighting about who got their snouts deeper in the trough, rather than fighting for real people.

After a decade in the South Australian Parliament from 1997, Senator Xenophon moved across to federal politics in 2007.

He said he did that because he believed he could do more for his state as an independent in Canberra.

He said since South Australia's massive power blackout last year and record power prices, he concluded the state's problems could not be fixed in Canberra without first fixing what he called a "broken political system back home".

Who will replace Nick Xenophon in the Senate? If Nick Xenophon is disqualified based on his citizenship, there will be a recount and Tim Storer will be elected. If he is not disqualified, when he resigns, his party can nominate the replacement. Either way, there will be another Nick Xenophon person in the Upper House. It will actually give more face to the other three members of the party that are currently there. Nick does nominate them. In the seat of Hartley that he is running for in SA, 2.4 is the margin. The election of Hartley always seems to be held by Italian speakers. It is where the Italian community heavily settled in Adelaide. He has lived there and it makes him competitive. It is currently held by the Liberal Party by Vincent Tavzia. NXT haven't stood in the lower house in SA before. That will be the big difference. It makes the contest for Government very different. Analysis by ABC election analyst Antony Green

Senator Xenophon will remain in the Senate until the High Court determines his citizenship status.

"I will remain in the Senate fighting for the state, until the High Court determines the outcome of the so-called citizenship case affecting me and six others," he said.

"While my lawyers are confident I will succeed, whatever the outcome, once that decision is handed down I will be in a position to leave the Senate."

He will then contest the South Australian seat of Hartley, centred around Adelaide's inner north-eastern suburbs.

"Running for the seat of Hartley will be a big gamble for me, even though, as you know, I'm not a gambler," Senator Xenophon said.

"I'm sure that both Labor and the Liberals will pull out all the stops to try to prevent me and my team from breaking through into State Parliament.

"They don't want their cosy little duopoly broken up. I'm sure they will throw everything at us.

"So, I expect plenty of dirty tricks. Plenty of mud will be thrown, probably the kitchen sink as well.

"For my part, it will be a do or die effort."

Sorry, this video has expired Xenophon says citizenship row did not influence decision to return to state politics

Senator Xenophon said in the days and weeks ahead he would be announcing at least a dozen other candidates who would run for State Parliament with him under his "SA-BEST" banner.

He said he would then talk about the issues and policies he wanted to focus on in the run up to the March 2018 poll.

SA state politics 'broken' and 'politically bankrupt'

Senator Xenophon has described the state of South Australian politics as "a triumph of low expectations".

"Just keeping the lights on over the next summer will be presented by the Government as a major achievement to be lauded and applauded. It's embarrassing," he said.

"Our state politics is broken, politically bankrupt ... We have the same old soap opera script between Labor and Liberal, but little real policy debate, let alone solutions for the state's many troubles.

"To quote Shakespeare, it seems our State Parliament has become nothing more than a stage for a troupe of players, led by the Premier and the Opposition Leader.

Loading

"We need deep and lasting reforms to put an end to the shallow political games our self-proclaimed leaders like to play, and get South Australia back on the right path.

"The fact is Labor has been taking us down the wrong path, and the Liberals want to take us to a dead end.

"We have a government that deserves to lose, and an Opposition that does not deserve to win."

Nick Xenophon is well known for using colourful stunts to get his message across. ( ABC News: Chris McLoughlin )



Hartley a marginal seat

Hartley has a 2.4 per cent margin and is centred around Adelaide's lower north-eastern suburbs.

It sits inside the federal seat of Sturt, held by Liberal frontbencher Christopher Pyne.

Senator Xenophon's federal party, NXT, put a lot of effort into trying to win Sturt at the last federal poll.

The ABC's Election analyst, Antony Green, noted that Hartley always seemed to be held by Italian speakers, as it was where the Italian community heavily settled in Adelaide.

Sorry, this video has expired Xenophon return to state politics puts 'a whole new spectrum' on upcoming election

"He has lived there and it makes him competitive. It is held by the Liberal Party by Vincent Tarzia," Mr Green said.

"The next South Australian election will be a three-party contest — Liberal, Labor and Nick Xenophon's SA Best. Who will win depends on what happens with preferences.

"It could be Labor minority backed by Nick Xenophon or Liberal minority backed by Nick Xenophon.

"It is the biggest shake-up in two-party politics in decades in Australia."

Seeking more than the donkey vote: Senator Xenophon wants the balance of power in SA. ( Supplied: The Monthly )

Greens wish Nick Xenophon well

The Greens have wished Senator Xenophon "good luck" with his new move.

"We need more non-major party MPs in lower houses chambers across the country," Greens senator Sarah Hanson-Young said.

"More diversity in houses of government is good for democracy.

"Nick Xenophon has made a valued contribution to the Senate throughout his federal career. We have worked well together fighting for local jobs and protecting the Murray, and while he and I were not on the same side on all issues, we share a passion for South Australia."

The next SA election is just five months away. ( Twitter: Nick Xenophon )

Xenophon 'satisfying his ego': Pyne

Federal Government Minister Christopher Pyne has accused Senator Xenophon of quitting the Senate to satisfy his own ego.

"I've known Nick Xenophon for many decades. He loves politics, he loves the game of politics, he doesn't deliver outcomes," Mr Pyne said.

"This is the latest example of him putting his massive oversized ego in front of the people of South Australia's interests.

Loading

"It's about the next election's in march in South Australia [and] he can't bear not to be in it."

South Australia's Opposition Leader Steven Marshall said Senator Xenophon had not ruled out giving Labor a fifth term in government.

"The people of South Australia voted at the last election, and the election before that, to chuck Labor out," Mr Marshall said.

"This is our big opportunity in March of next year. Let's hope Nick Xenophon doesn't give Labor a fifth term.

"This would be a disaster for our state... we've got to do everything we can to make sure that doesn't become a reality.

"The people of South Australia deserve a new government, a majority government, a reformist government to get this state back on track."

The state's Treasurer, Tom Koutsantonis, argued that Nick Xenophon was taking advantage of what he called a "massive split" on the right side of SA politics.

Vincent Tarzia (L) is the current Hartley MP in Opposition Leader Steven Marshall's (R) Liberal team. ( ABC News: Dean Faulkner )

Loading...