Donald Trump accuses Ted Cruz of fraud in Iowa, demands re-vote

Ted Cruz was accused of allegedly lying to thousands of voters about Trump's policies

Donald Trump went on the offensive today, accusing Republican rival Ted Cruz of stealing victory in Iowa as he sought to burnish his standing ahead of next week's primary voting in New Hampshire.

The real estate mogul made the sensational accusations on Twitter, telling his six million followers that the first-time senator from Texas had committed fraud in the first caucus of the 2016 US presidential election.

"Ted Cruz didn't win Iowa, he stole it. That is why all of the polls were so wrong and why he got far more votes than anticipated. Bad!" Trump wrote.

He criticised Cruz for putting out a statement saying that a fellow candidate, retired neurosurgeon Ben Carson, was quitting the race, and accused Cruz of lying to thousands of voters about Trump's policies.

"Based on the fraud committed by Senator Ted Cruz during the Iowa Caucus, either a new election should take place or Cruz results nullified," Trump wrote.

The accusations, the latest in a long line of Trump insults aimed at his rivals, come in stark contrast to his gracious concession speech in Iowa on Monday, saying he was "honored" to finish second.

His tally -- just above 24%, for second place after Cruz and just ahead of Senator Marco Rubio -- in the first vote after months of wall-to-wall media coverage raises serious questions about whether showmanship has a winning strategy.

A second hiccup, at the New Hampshire primary next Tuesday, would spell political disaster for the billionaire.

Cruz won 27.7% of the vote in the Republican caucus in Iowa, staking his claim to be the new standard bearer of the right.

Rubio, whose star has risen in recent weeks, won more than 23%, anointing him as the Republican establishment candidate of choice best placed to defeat presumed Democratic nominee Hillary Clinton.

Polls put Trump firmly ahead among Republican voters in New Hampshire, but analysts warn that anything less than a win in Tuesday's primary will further damage his campaign message that he is a winner.

Jeanne Zaino, a professor of political science in New York, said Trump's outburst was a strategic move designed to counter the narrative that he lost in Iowa and that his campaign is beatable.