For a turkey to be deemed organic, 80 per cent of its total feed must be organic.

Of the non-organic remainder, which often comprises full-fat soya bean, it must be accompanied by a certificate to show it is GMO free. (In the case of free range, the turkeys' feed formula, during the fattening stage, must be at least 70 per cent cereal.)

Organic turkeys must also have more space - both indoors and outdoors - than their intensively-reared counterparts. (Free-range birds must have "adequate access" to open-air runs, with four metres square allowed per bird.)

Turkeys raised organically cannot be given certain medication.

There are only a few organic turkey farmers in Ireland, but all of the major supermarkets will be stocking organic birds for Christmas. Out of the 40,000 turkeys Superquinn will be stocking, about 1,000 will be organic, at €11.99 a kilo; Dunnes Stores said it has yet to decide how many it would stock and what price it would sell them; Tesco will stock 15 per cent more organic turkeys this Christmas and has yet to set a price; only 150 out of the almost 65,000 turkeys stocked by SuperValu will be organic and a price has yet to be set. Marks & Spencer is selling organic turkeys, both instore and from its food brochure, at €13.99 a kilo. All the above supermarkets' organic turkeys are sourced in Ireland, except SuperValu's which are produced in England.