Celebrity chef Jamie Oliver’s restaurant Fifteen has been comprehensively condemned by a new London guide.

Harden’s London Restaurant Guide, which is based on reviews from 7,000 diners, gives Fifteen the lowest-possible ratings for food, service and ambience.

According to Harden’s reporters, Jamie Oliver is ‘seriously taking the piss’ with his ‘amateurish’ restaurant where ‘average’ food comes at ‘Gordon Ramsay prices’.

Fifteen was conceived as a TV reality show, in which the chef, who started at London’s highly-rated River Café and is one of the best-known faces on UK television, took a group of disadvantaged and often difficult teenagers and taught them to cook.

The deadline was November 2002, when the restaurant – whose profits go to charity – opened to massive publicity.

Since then reviews have see-sawed between excellent and not so good. Fay Maschler, one of London’s most formidable critics, said her meal ‘contained some of the best dishes I have been served in a long time.’

But nothing has been as bad as the Guide’s co-author Peter Harden’s assessment: ‘I can’t remember a restaurant run by a celebrity doing this poorly in 14 years – or one that charges this much money having such a poor showing.’

Customers’ gripes centre on the prices – £70 and more a head – which don’t reflect the quality of the food. One said, ’Just because it’s a charity doesn’t give them the right to rip people off.’

Decanter’s restaurant critic Brian St Pierre was amazed at the publicity – the reviews have literally gone round the world, appearing as main news items in New Zealand, Australia, the US and beyond.

‘It’s good quality food in the second tier,’ he said, ‘But it doesn’t deserve the attention either way. It doesn’t deserve a two-month wait to get a table, and it doesn’t deserve the publicity. I don’t think I’d go back there, and as for the prices, you just have to tell yourself it’s for a good cause.’

Jamie Oliver’s spokesman said the amount of thank-you letters they were getting, and the number of re-bookings, suggested it was going very well.

‘Whenever we get a complaint, changes are made where necessary. We take it all very seriously. All I can say is that a lot of famous people, and a lot of ordinary people, are coming and having a lovely time.’

At the other end of the scale, Gordon Ramsay’s flagship Chelsea restaurant – called Gordon Ramsay – was praised for its ‘world-class form’ and ‘exhilaratingly good’ cuisine.

The Ivy was voted Londoners’ favourite restaurant followed by Chez Bruce, J Sheekey, Le Caprice and Gordon Ramsay.

Written by Adam Lechmere