They have become the glamorous faces of domestic bliss. But Nigella Lawson has rounded on her American rival, Martha Stewart, in a public and acrimonious spat.

The British TV chef claimed that Stewart had a “soft spot” for her husband, the multimillionaire art collector, Charles Saatchi, and had tried to disparage her.

The feud began when Lawson came to prominence in the US. Stewart, sensing that her English counterpart represented a threat to her position as America’s domestic guru, dismissed her rival as “what’s her name who married the Saatchi”. Media commentators speculated that Lawson had gone to America after Stewart, once named the third-most-powerful woman in the country, fell from grace on being convicted and jailed for stock market fraud in 2004.

In this week’s edition of the Radio Times, Lawson claimed that Stewart, 66, had “insecurities”. She said: “I know her, and I suspect she has a soft spot for Charles. I’m sorry that even though she’s so great and successful she has to disparage someone else. It’s not necessary, but everyone has his or her insecurities. You should try to keep them to yourself and behave in a confident way.”

Lawson, 47, admitted to having her own insecurities, about her weight. And in the interview, to promote her new 13-part BBC Two series, Nigella Express, she acknowledged that her chat show, launched on ITV1 in 2005, had been unsuccessful. “I knew it wasn’t me,” she said. “On the first show, I was so frightened I thought I’d never come out of my dressing room.”

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