Ted Cruz, Donald Trump’s former rival, was booed off the Republican top stage on Wednesday night after he withheld his endorsement of the New York billionaire as the nominee.

“Stand, and speak, and vote your conscience, vote for candidates up and down the ticket who you trust to defend our freedom and to be faithful to the Constitution,” Ted Cruz said at the party’s convention, instead of urging Republicans to rally behind Trump, reports Xinhua news agency.

The language, which echoed statements from the ‘Never Trump’ movement, triggered boos and chants of “Trump! Trump!” from the audience.

“We’re not fighting for one particular candidate or one particular campaign,” Cruz said.

“We deserve leaders who stand for principle, unite us all behind shared values, cast aside anger for love. That is the standard we should expect, from everybody.”

Cruz left the stage putting on a brave face, wrapping up his remarks and thanking the audience while Trump entered the venue and gave his formal rival a thumbs-up, sarcastically venting his anger.

Cruz came second to Trump during the Republican primaries.

The two men have shared a notoriously hostile rapport following a primary battle that grew uncharacteristically nasty, with Trump labelling Cruz a “liar”.

On the final day of Cruz’s campaign in May, he charged Trump with being “a pathological liar”, “a narcissist” and “utterly immoral”, the Guardian reported.