Over a series of messages DonaldTrump personally insulted the host of the UK version of The Apprentice branding him ‘dopey’ and suggesting Sugar would be nothing without him.
Trump, who hosts the US version of the show, tweeted: “When I made the Apprentice the #1 show in the US, that was a good day for you...and many others. Drop to your knees, Sugar, and say thank you, Mr Trump”.
He added: “Look in the mirror and thank the real Lord that Donald Trump exists. You are nothing!”
Although there are no signs of any response from Lord Sugar this morning, the gossip website DigitalSpy says Sugar did reply – suggesting he has subsequently deleted his tweets.
The spat apparently began when Donald Trump criticised “garbage wind turbine” subsidies in Scotland, saying they are destroying the country and Scottish people don’t want them.
Sugar allegedly responded to the tweet by say that, in fact, it is Trump himself that Scots don’t want.
Several messages about wind turbines were then exchanged, with Trump going on to question Sugar’s skills as a businessman, suggesting he “should not be doing The Apprentice”.
Trump went on to tweet: “Sugar - 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”.
According to Digital Spy, Sugar responded: ““You approved me! What a load of rubbish dream on You don't own apprentice Mark Burnett does. Shut up and argue with Obama. Success is measured with what you have in business. I own all my real estate with no bank borrowing how about you big shot?”
The Twitter spat then got increasingly personal, with Trump continuing to assert that Sugar’s celebrity status is down to him and suggesting Sugar has “little persona”.
Sugar responded by saying Trump had “had a charisma bypass”.
At this point Piers Morgan waded into the row, suggesting Trump fire Sugar from The Apprentice.
Morgan tweeted: “Don't wish to interfere obviously @realDonaldTrump - but it may be time to fire @Lord_Sugar from YOUR show for his impertinence?”
The exchange continued with Sugar mocking Trump for having less followers than him on Twitter, before former Labour spin doctor Alistair Campbell waded in to question Trump’s motivations for his Scottish wind turbine concern.
Caitlin Moran tweeted during the exchange: “Lord Sugar vs Donald Trump on Twitter is like a 50ft high Mr Burns and a 50ft high Del Boy fighting in the middle of Tokyo #rivetted”.