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 USD 200 million he inherited from his wealthy father.

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.

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

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,'' 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.

Latest News from World News Desk