I think Jeremy Corbyn just saw his career flash in front of him. With all this talk about travel bans and official visits to the UK by disreputable individuals, the Labour leader must surely be yearning for a simpler time when, before greatness was thrust upon him, he could go about his business as an anonymous back bench Labour MP, healing the world with his special blend of love, harmony and peace-seeking.

He’d like to buy the world a Coke, were it not for his antipathy to US-based soft drinks conglomerates.

So of course he has spent the last few days – hasn’t everyone? – fulminating against the new US president, Donald Trump, and his justifiably-ridiculed Muslim travel ban.

Indeed, he told the BBC's Robert Peston: "It would be totally wrong for him to come here while that situation is going on. I think he has to be challenged on this. I'm not happy on him coming here until that ban is lifted."