Battle of the frying pans: TV chef Clarissa Dickson Wright attacks 'force for spin' Jamie Oliver

But this time Clarissa Dickson Wright has brought her rivalry with Jamie Oliver to boiling point.

Miss Dickson Wright - once one of the Two Fat Ladies - described the television chef's restaurants as 'lacklustre'.

Boiling point: Clarissa Dickson Wright has taken another dig at Jamie Oliver

Sticking the knife in again, she even suggested the food served in them might not be safe to eat.

'He is a brilliant cook,' said Miss Dickson Wright. 'Unfortunately his restaurants are very lacklustre - I'm told.

'I don't know. I don't eat in them... I don't want to risk being poisoned.'

She also appeared to echo earlier criticisms of Oliver for performing in advertisements for Sainsbury's.

'The reason I get so cross is that he could have been such a force for good, as opposed to a force for spin,' said Miss Dickson Wright, 61.

Criticised: Jamie Oliver at his Fifteen restaurant, launched following the TV series Jamie's Kitchen

She also renewed her attacks on Oliver's campaign to make school dinners healthier, saying: 'Children don't eat salad!

'All it succeeded in doing was getting more schools to close down their meal functions.'

And, finally she had a go at Oliver's mother Sally for sticking up for her son against her earlier criticisms, declaring: 'Defending her baby boy, was she?

'It's ridiculous, like EastEnders, or one of those soaps I don't watch.'

Miss Dickson Wright began finding fault with 33-year-old Oliver in 2004, accusing him of selling his soul to Sainsbury's.

The Two Fat ladies: Jennifer Paterson and Clarissa Dickson Wright

The topic came up again this year, when she pointed out she had rejected a £2million offer from the store to promote its products.

'We turned them down - I think supermarkets are the anti-Christ,' she said.

Referring to her former partner in the Two Fat Ladies cookery series, she added: 'Jamie Oliver hasn't done anything Jennifer Patterson didn't do years ago - and she didn't sell her soul to Sainsbury's.'

This prompted Oliver's mother to join the fray, saying Miss Dickson Wright's dismissal of her son's efforts to improve school dinners were 'crass beyond measure'.

'I know Jamie is perfectly capable of looking after himself, but he is not at all bitchy and has never done anything to Clarissa,' she said.

Miss Dickson Wright, a barrister, and Miss Patterson emerged as the Two Fat Ladies in 1996. The series ended with the death of Miss Patterson eight years ago.

Oliver conceived and established the Fifteen restaurant chain, which helps disadvantaged young people work in the hospitality industry.

His fight to ban unhealthy food in schools was chronicled in the TV series Jamie's School Dinners.

Unusually, his spokesman responded to Miss Dickson Wright's latest comments.

'Clarissa has no fear of being poisoned... because I suspect none of our restaurants would welcome her, for fear of offending the other guests,' said the spokesman.