US billionaire Donald Trump has bitterly attacked Lord Sugar as “never successful” enough.
Mr Trump fronts the American version of the tv show The Apprentice.
In a Twitter attack on the BBC star, Mr Trump told the self-made Londoner: “Unlike you, I own The Apprentice. You were never successful enough.”
The spat, over the last 24 hours, was ignited by Lord Sugar’s support of the UK government subsidising Scottish windmills.