A furious war of words has erupted between Lord Alan Sugar and TV property expert Kirstie Allsop after the pair criticised each other on Twitter.

Lord Sugar hit back after Kirstie, who presents Location Location Location on Channel 4, called The Apprentice star “shockingly uncharitable” in one of her tweets.

“Being asked whether I follow Alan Sugar. I worked with him on Sport Relief Does The Apprentice,” she said on the social networking site.

“His behaviour was shockingly uncharitable. There are words I don’t use, but when it comes to Sugar and his treatment of the staff and crew involved, in any other workplace he’d be fired.”

Lord Sugar, meanwhile, retorted by calling Kirstie “the worst contestant in Celeb Apprentice ever”.

“More lies from Kirstie Allsop,” he said on his own Twitter page. “She said I was hard on and very rude to production people on Celeb Apprentice.

“You are liar. Don’t tweet lies about me. By the way you were the worst celeb ever in Celeb Apprentice.”

Lord Sugar is currently back on TV screens in the sixth series of the show which began on Wednesday night.