Celebrity chef Delia Smith - a champion of British cooking for more than 40 years - has frustrated her fans by telling them to eat lamb from New Zealand.
The celebrity cook, 67, has been urging British housewives and chefs on her official website to "Make it New Zealand lamb every time".
Her loyalty has been turned by an advertising deal which includes an offer for her readers of a free trip to New Zealand.
Her advice has angered her fans, as well as struggling farmers, who are begging consumers to ignore it and buy domestically reared lamb, the Daily Mail newspaper reported.
"Lately Delia Smith's loyalties seem to have become a little scrambled," the paper said.
Meat and Wool New Zealand chief executive Scott Champion confirmed the company had drawn Miss Smith into their advertising strategy because of her influence on the British market. A comprehensive campaign was started in Britain in February to reverse a 15 per cent drop in exports.
"She is so well recognised and it is a bit of a go-to site for British households looking for a recipe. Her name generates huge amount of traffic from the sort of demographic we are interested in," said Mr Champion.
This year the Guardian reported British consumers used Miss Smith's cookbooks like shopping lists.
After her book How to Cheat at Cooking sold 48,000 copies within two days of its February release, the newspaper said the "Delia effect" was as potent as ever.
Sales of Marks and Spencer tinned lamb rocketed 200 per cent after the chef recommended it in her shepherd's pie recipe.
Her endorsement of Fairtrade chocolate sauce, Aunt Bessie's frozen mash and Italian meats also sparked increases in sales.
The lamb row blew up as Miss Smith was made a CBE in Britain's Queen's Birthday Honours list for teaching Britons how to cook and for services to the nation's food industry.
"When treating friends and family to luscious barbecue lamb recipes or feeding the family during the week, you need to know that the meat you're buying and cooking is of the highest quality, reared to exacting standards," she wrote on her website.
"Which is why New Zealand lamb is a great choice, whatever the occasion."
She goes on to describe the "lush pasturelands" where the lambs graze in the sunshine, giving the meat its "great flavour and eating quality".
Website reader Lewis Palframan said: "I'm gobsmacked and disappointed. In the age of food miles and carbon footprints - not to mention the need for supporting British farming - what on earth is wrong with our own lamb?"
The British National Farmers' Union responded by stating British lamb was produced to the highest welfare standards possible.
Miss Smith's promotion of New Zealand lamb conflicts with Britain's larger buy-local programme which also saw a British dairy company try to entice consumers away from New Zealand butter.
Country Life recruited Sex Pistols frontman John Lydon aka Johnny Rotten to sway buyers from New Zealand's Anchor butter, after research showed 40 per cent of Britons thought Anchor was a British brand.
- ADDITIONAL REPORTING: NZPA