Des Moines, United States: Donald Trump intensified his feud with Fox News just days before Iowa kicks off the presidential nominations contest, saying he will hold a rogue event Thursday while Republican rivals take part in a debate without him.

The celebrity TV star billionaire, 69, who has never held elected office, left the Republican Party dumbfounded with his bombshell announcement late Tuesday that he will not participate in the debate in Des Moines, Iowa, hosted by Fox News.

All eyes are on the heartland state, where the 12 Republican candidates and three Democratic hopefuls including Hillary Clinton are vying for bragging rights and the lead in the primary race heading to subsequent votes in New Hampshire, South Carolina and Nevada.

‘Mr. Trump knows a bad deal when he sees one,’ his campaign team said, after Fox took the unprecedented step of mocking Trump for asking his nearly six million Twitter followers to weigh in on whether or not he should attend the debate.

Fox shot back that it would not give in to ‘terrorizations,’ after it accused Trump’s campaign manager of threatening Fox News host and debate moderator Megyn Kelly.

Twisting the knife, Trump said Wednesday he will hold a ‘special event’ to benefit veterans groups at the same time as the debate, and in the same city.

Trump streaks ahead

The Republican National Committee appeared eager to distance itself from the Trump-Fox war.

‘We’d love all the candidates in,’ RNC spokesman Sean Spicer told CNN.

But ‘at the end of the day, each campaign has to make up their own mind as to what’s in their best interest, and so we respect that decision.’

Trump has a genuine battle on his hands in Iowa with ultra-conservative Senator Ted Cruz, his nearest GOP rival, trailing by about five percentage points in the RealClearPolitics average of recent Iowa polls.

According to Cruz, the race is dead even.

Nationally, however, Trump is far ahead. A new CNN/ORC poll of Republican voters has Trump at 41 per cent to 19 per cent for Cruz, with more than two-thirds of Republicans saying they believe the billionaire will be the party’s presidential candidate.

Florida Senator Marco Rubio is a distant third, at eight percent, followed by retired neurosurgeon Ben Carson at six percent and former Florida governor Jeb Bush at five percent.

Cruz warned evangelical pastors in Iowa that if Trump manages to win there and then in New Hampshire, he could prove ‘unstoppable.’

Cruz at centre stage

With Trump absent, Cruz will be centre stage Thursday with six other Republicans in Des Moines, totally changing the debate dynamics.

Cruz hit out at his rival, accusing him of being ‘afraid’ to take part in the debate and challenging him to a one-on-one debate.

With Trump gone, the other candidates will likely focus their fire on Cruz.

Chris Christie, the governor of New Jersey, said Trump’s snub was a mistake.

‘I’m glad he’s not coming, from my perspective. It’s more time for the rest of us on the stage,’ Christie told Boston Herald Radio.

Trump’s team meanwhile taunted Fox, predicting that advertisers will be furious when the billionaire’s absence results in lower viewership.

Rush Limbaugh, the influential arch-conservative radio talkshow host, said Trump was ‘so far outside the formula that has been established for American politics that people who are inside the formula can’t comprehend it.’

‘They’re angry, they are flabbergasted, they’re shocked, they’re stunned — and all of it because he’s leading.’

Writing on Facebook, Limbaugh added: ‘You can’t just cover Donald J. Trump from the prism of news. You have to cover Trump also through the entertainment prism.’

Don’t forget the Democrats

In the Democratic race, Senator Bernie Sanders is running neck-and-neck with former secretary of state Clinton.

The independent senator from Vermont on Wednesday spent an hour in the Oval Office with President Barack Obama discussing foreign and domestic policy, as well as the campaign.

Sanders, 74, a self-described Democratic Socialist who is generating great enthusiasm among young voters, said the Iowa result will come down to turnout.

‘If there is a large turnout, I think we win,’ he told reporters. ‘If not, I think we’re going to be struggling.’