“Khan reminds me very much of our very dumb and incompetent Mayor of NYC, de Blasio, who has also done a terrible job — only half his height,” he wrote.

His comments came after Khan wrote an opinion piece in The Observer newspaper on Sunday condemning Trump’s state visit and grouping him together with far-right leaders in Europe.

“It’s so un-British to be rolling out the red carpet this week for a formal state visit for a president whose divisive behaviour flies in the face of the ideals America was founded upon — equality, liberty and religious freedom,” wrote Khan, who is the son of a Pakistani bus driver.