Billionaire businessman Clive Palmer has abandoned his plans to contest the country's most marginal seat, instead throwing himself into the race for the Senate.

Key points: Mr Palmer says he's confident he can win a Senate seat

Mr Palmer says he's confident he can win a Senate seat Former rugby league player Greg Dowling will contest the Townsville seat of Herbert

Former rugby league player Greg Dowling will contest the Townsville seat of Herbert Mr Palmer is taking a fight to change how Senate results are released to the High Court

The former federal MP was tipped to run in the north Queensland seat of Herbert, but has catapulted ex-rugby league star Greg Dowling into the contest, leaving Mr Palmer to focus his attention on an elusive Senate spot.

"We'll win," Mr Palmer said.

"You'll see that we'll be in the Senate. There's no question about that.

"I'm confident as far as the party goes that we'll have the balance of power in the Senate."

Mr Dowling, a former State of Origin player, has been revealed as the United Australia Party's "star" candidate for Herbert, which is currently held by Labor's Cathy O'Toole by 0.02 per cent.

"I'm not scared to go into Parliament to take on the hard tasks," Mr Dowling said.

"I'm ready for it. I'm committed to it and I'm committed to the United Australia Party.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 26 seconds 26 s Greg Dowling's infamous fight with Kiwi Kevin Tamati in 1985

"I've been in business [in Townsville] for 10 years and it's hard. And a lot of people are suffering."

Mr Palmer's popularity in the regional city took a major hit after the collapse of his Queensland Nickel business in 2016, which left 800 workers unemployed and debts of about $300 million.

The businessman has always maintained he didn't owe any money to cover the entitlements of workers, but earlier this week he announced plans to pay back any outstanding funds.

That amount will be a fraction of the $300 million originally owed to creditors including workers, local businesses, and the Federal Government.

Mr Palmer denied the promise was politically motivated and a notice placed on the Queensland Nickel website overnight revealed workers would not get payments until three days after the federal election.

Queensland has six Senate spots up for grabs.

Political analysts say it is unlikely Mr Palmer will get enough votes to secure a position after competing with bigger names including LNP, Labor, Greens and One Nation.

"The reason that people want to have a go at us is that they're afraid we might do something for the Australian people," Mr Palmer said.

United Australia Party candidate for Herbert Greg Dowling and party founder Clive Palmer. ( ABC News: Sofie Wainwright )

High court challenge

Mr Palmer is also waging another electoral battle — this time in the High Court, to delay the release of preliminary polling results of the federal election.

The businessman wants the High Court to ban the Australian Electoral Commission from releasing any results until all polls have closed.

If successful, it would mean there would be no results from the count until about 9:30pm (AEST) on May 18, when polling stations in the Cocos Islands close.

The Cocos Islands are a small archipelago in the Indian Ocean where about 550 people reside.

The High Court has set a hearing date for May 6 — 12 days before the election.