Lord Sugar stepped up his online feud with Kirstie Allsopp with a below the belt comment telling her to lose weight.
The straight-talking Apprentice guru said she should consider "a diet" after he saw a clip of the Channel 4 property presenter.
The exchange is the latest in a lengthy to-and-fro between the pair which erupted on networking site Twitter.
Thursday's episode began when Lord Sugar reminded his online followers to observe the two minute silence this morning. Another Tweet followed shortly afterwards which he blamed on a technical glitch.
But Kirstie spotted the remark and wrote: "Using the 2 minutes silence to plug your book? That's unforgivable by anyones standards!"
Lord Sugar reiterated his claim that there had been a technical problem and responded that having seen a "clip of her TV show, she really needs to think about a diet".
He also drew attention to an expletive on Kirstie's Twitter account and asked: "Did you pick that language up at Roedean Darling lovie?"
Problems between the pair erupted a month ago when they began a slanging match on the social networking site. They had briefly worked together on a celebrity version of BBC show The Apprentice.
Last month she wrote of Lord Sugar: "I worked with him on Sport Relief Does The Apprentice. His behaviour was shockingly uncharitable." She later added: "There r words I don't use, but when it comes to Sugar & his treatment of the staff & crew involved... in any other work place he'd be Fired!!"
He later said of Kirstie, who walked out of the charity show, that she was "a lying cow" and said she was the "worst contestant on celeb apprentice ever".