Keir Starmer should be prepared to use populist Reform UK leader Nigel Farage as a “bridgehead” to working with US President-elect Donald Trump, according to a key ally of the British prime minister who’s tipped to become the UK’s next ambassador to Washington.

Lord Peter Mandelson has urged Sir Keir Starmer to use Nigel Farage as a bridge between Donald Trump’s incoming administration and the UK.The Labour peer, who is the favourite to be named as the next British ambassador to the UK,