W hen Barack Obama intervened in the EU referendum, claiming the UK would be at the “back of the queue” in any trade deal with America, he faced the wrath of Brexiteers who were incandescent with his comments.

Nigel Farage, then the leader of Ukip, accused the US president of behaving “disgracefully”, and even went as far as to praise the Russian president Vladimir Putin for maintaining his “silence throughout the whole campaign”.