US presidential elections: Donald Trump called 'crazy zealot' as rivals attack him

Trump came under attack from Ted Cruz, Marco Rubio on his immigration stand and for hiring foreigners in his business projects

Republican presidential frontrunner Donald Trump today came under scathing attack from rivals Ted Cruz and Marco Rubio who blasted the real estate mogul on his immigration stand and for hiring foreigners in his business projects, as the debate turned shriller ahead of the crucial "Super Tuesday".

While Cruz called Trump, who has vowed to check migrants and transfer of jobs to non-Americans, a "crazy zealot", in a feisty exchange of words during a primary debate in Houston, Rubio alleged that real estate mogul would have been selling watches but for the $200 million he inherited from his wealthy father.

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The tone reflected the fierce battle underway ahead of "Super Tuesday" on March 1, when 11 states including Cruz's huge home state of Texas go to the polls in perhaps the most consequential voting day of the 2016 primary campaign.

Rubio attacked the real estate billionaire for having "hired a significant number of people from other countries to take jobs that Americans could have filled" in Trump development projects.

He pointed to articles that described a 1980s lawsuit by a workers union against Trump for hiring 200 illegal immigrants from Poland to build Trump Tower in New York.

Trump replied back fiercely, saying, "I've hired tens of thousands of people...You haven't hired one person, you liar."

He reminded Rubio of his poor performance in the last debate, saying that he had never seen that kind of a meltdown.

"This guy (Rubio) is a choke artist and this guy (Cruz) is a liar," the billionaire-turned-politician charged the two of his presidential rivals standing on his either side.

Throughout the debate, both Rubio and Cruz were seen trying their best to nail down Trump.

"I funded you. I gave you check," Trump told Cruz.

"You gave me $5,000," the Texas Senator said, in another sharp exchange of words between the two.

At the start of the debate when the questions were posed on immigration, Trump castigated Cruz that he was trying to pretend to be "Robin Hood".

"Here's a man -- Robin Hood. This is Robin Hood over here. He talks about corruption. On his financial disclosure form, he did not even put that he's borrowed money from Citibank and from Goldman Sachs, which is a total violation. He didn't talk about the fact that he pays almost no interest. He just left it off, and now he's going to protect the people from the big bad banks," Trump alleged.

However, the longest heated exchange of words was between Trump and Rubio when they were posed questions on the proposal to build a wall on the US-Mexico border.

"Here's a guy that inherited $200 million. If he hadn't inherited $200 million, you know where Donald Trump would be right now?...Selling watches," which was interrupted by a huge applause.

"That is wrong. I took $1 million and I turned into $10 billion," Trump said.

Rubio doubted the answer and then challenged Trump to release his tax returns, which he has not done so far.