Republican frontrunner for US presidential elections Donald Trump dealt with strong blows from rivals at the GOP debate hosted by the Fox News on Thursday. The attacks followed severe criticisms by the party’s veteran politicians after Trump recorded impressive wins in seven of the 12 states that went into polls on Super Tuesday.

Trump, who is now being regarded as the possible Republican presidential candidate, took the stage with rivals Marco Rubio and Ted Cruz at the debate which was held at the Fox Studio in Detroit. Rubio said that Trump deserved to be attacked because he mocked others relentlessly.

The Republicans fear that that if Trump is chosen as the Republican candidate for the finals run in November, he will lose the party’s bid, the BBC reported.

At the beginning of the debate, Trump was asked about an attack by 2012 nominee Mitt Romney earlier that day. Romney had called Trump a bully, fraud, greedy and misogynist. He also said that Trump’s policies that include banning all Muslims around the world from entering the US as well as deportation of undocumented migrants would only make the world a less safe place.

However, Trump dismissed the criticisms leveled against him by Romney as he was a “failed candidate” but he soon found himself striving to fend off the attacks that came his way from Rubio and Cruz.

Trump even had to shout insults to stop Rubio from criticising him.

“You’ve defrauded the people of Florida, little Marco!” Trump repeated after Rubio hammered him on his involvement in the troubled “Trump University.” Cruz teamed up with Rubio in attacking the billionaire and attempted to turn their argument itself into evidence against him.

“Let me just [ask] the voters at home: is this the debate you want playing out in the general election?” Trump said.

“If we nominate Donald, we’re going to spend the fall and the summer with the Republican nominee facing a fraud trial,” Cruz said. He referred to a suit that is progress and may come up for trial this summers, the Washington Post reported.

Rubio also criticised Trump for getting his clothing line outsourced to China and Mexico and Trump promised he would move it back to the US.