Asda has been aiming for a 100% British crop on its shelves for the past three years, although it admitted it faced a one-week supply gap this year, which was filled by imports.
Meanwhile, Hugh Mowat, vegetable technologist with Marks & Spencer, said he was 99% sure the company would be able to go straight from over-wintered Scottish stock on to Suffolk produce in 2005.
Morrisons is also thought to be developing an all-British supply system.
But there are fears that retailers’ ambitions may be stymied by global warming.
John Birkenshaw, secretary of the British Carrot Growers’ Association, said that soil temperatures in the last three winters had failed to fall to the optimum 4C which meant producing a crop large enough to last until next spring would be difficult.