Nigella Lawson accused her ex-husband Charles Saatchi of threatening to ‘destroy’ her as she gave evidence in the trial of their former personal assistants on fraud charges.

The TV cook, 53, was greeted by dozens of photographers and television crews outside Isleworth Crown Court in west London as she arrived this morning (December 4).

It is alleged that between January 1, 2008 and December 31, 2012, Italian sisters Elisabetta, 41, sometimes referred to as Lisa, and Francesca Grillo, 35, committed fraud by abusing their positions as PAs by using a company credit card for personal gain. The pair, of Kensington Gardens Square, Bayswater, west London, deny the charge.

Nigella, dressed entirely in black apart from a white collar on her shirt, said: “I have been put on trial here where I am called to answer, and glad to answer the allegations, and the world’s press, and it comes after a long summer of bullying and abuse. I find it’s another chapter in that.”

She admitted she had been reluctant to give evidence, and spoke of ex-husband Mr Saatchi’s reaction to her reluctance. “He had said to me if I didn’t get back to him and clear his name he would destroy me,” she said.

Nigella said following the ‘awful incident at Scotts (restaurant)’, false allegations of drug use began circulating on a ‘PR blog’. She said these allegations on the blog were ‘dedicated to salvaging Mr Saatchi’s reputation and destroying mine’.

Speaking about Lisa, she said: “It’s very difficult when you find out that someone you have loved and trusted could behave that way. In my heart of hearts I do not believe Lisa to be a bad person. I believe her not to have a very strong moral compass.”

The court heard last week that the Grillo sisters lived the ‘high life’, spending the money on designer clothes and handbags. Jurors have heard they are accused of using credit cards loaned to them by the cook and her ex-husband Mr Saatchi to spend more than £685,000 on themselves.

Regarding Lisa, Nigella said: “Lisa had been a stalwart and had helped me through a very difficult time when my first husband died. I loved Lisa. My children loved Lisa. She came to me at a very difficult time in my life. She was a rock. I would have done anything for her.”

Nigella said Lisa left the job at one point and she continued to pay her for three months so she would not get ‘too anguished’ about finding a new job.

She added: “I didn’t want her to feel that she had to stay with me.”

On Lisa’s return, she was ‘increasingly bitter’, Nigella said. “She broke our heart.”

Nigella became agitated at the line of questioning from defence barrister Anthony Metzer QC. When asked if she would agree that she shared a liberal and bohemian background with her late husband John Diamond, she said: “I fear my father might take exception to that.”

He also asked her if Mr Saatchi had a temper. “Yes, he did have a temper and I don’t think that anyone can be in any doubt he had a temper,” she said.

When asked if she thought Mr Saatchi’s background conflicted with hers, she said: “I don’t understand why my marriage is pertinent to you.”

When asked by Mr Metzer if her PAs were expected to look ‘presentable’, she laughed at the notion, saying: “I’m afraid to say that I often do not look presentable. I don’t really mind about appearances.”

Mr Metzer asked whether Nigella ‘confided’ in Lisa about Mr Saatchi’s temper. “Yes,” she replied.

The barrister then asked whether she discussed with Lisa that she was contemplating leaving her then husband.

“It wasn’t so much a discussion,” she said. “I may have said I didn’t know how much longer I could take this.”

She also said she had ‘absolutely no idea’ about the limits on the credit cards given to the defendants.

The chef said she was ‘incredibly close’ to all of her assistants. “I tend to trust everyone implicitly and often that’s not rewarded,” she said.

She added: “I’m still trusting actually. I refuse to become a bitter, untrusting person.”

Nigella denied Mr Metzer’s claim that she would use credit cards belonging to Mr Saatchi to pay for exercise classes, manicures and pedicures. “I paid for them sometimes by cash and sometimes by cheque,” she said. “Personal trainers don’t take credit cards.”