The UK and the US pride themselves on their "special relationship", but it seems that Lord Alan Sugar and Donald Trump didn't get the memo.
The two, who both host versions of TV show The Apprentice in America and Britain, got involved in a Twitter war on Thursday, with Lord Sugar even invoking how many followers he had.
US Tycoon Trump told Sugar he was "dopey" and unsuccessful, writing on the micro-blogging website:
"Unlike you, I own The Apprentice. You were never successful enough to do The Apprentice but I approved you anyway. Without my show you’d be nothing!"
At one stage Piers Morgan also became involved, suggesting Trump might want to fire Sugar.
Trump had been provoked by Sugar who was outraged by his support for wind turbines.
Trump tweeted: ".@Lord_Sugar If you think ugly windmills are good for Scotland you are an even worse businessman than I thought…"
But when Sugar hit back, saying "the ugly windmills will bring more revenue and green power to Scotland than your golf project" the Twitter war commenced.
Sugar also told Trump he had "no power over the UK Apprentice" and accuses him of having a "fat ego."
We've reproduced the row in full below: