Donald Trump's first challenge after being crowned the Republican presidential nominee and delivering his vision for the White House will be to unite the party as fears grow following a chaotic convention in Cleveland that it may be permanently divided.

Newt Gingrich, the former House speaker, told The Telegraph that Ted Cruz, the runner-up to Mr Trump, now faces being entirely marginalised.

When asked whether Mr Cruz would be welcome at future Republican party events, Mr Gingrich said: "I doubt it."

Mr Cruz's convention speech on Wednesday in which he declined to endorse Mr Trump and attempted to undermine him was "selfish and destructive”, he said.