Britain's biggest-selling chocolate biscuit is going Fairtrade in the New Year in a "breakthrough" for the campaign to promote fairly traded goods, it has been announced.
From mid-January, Nestle's Kit Kat bars will bear the famous Fairtrade logo, boosting thousands of farmers in the Ivory Coast, from where the firm buys cocoa.
Around a billion bars of the York-based brand are sold in this country every year, and Fairtrade campaigners hope the announcement will persuade other food companies to follow suit.
Harriet Lamb, of the Fairtrade Foundation, estimated that farmers will receive hundreds of thousands of pounds more next year as a result of receiving a "fairtrade price" for their cocoa, which she hoped will help tackle poverty levels in the country.
"The significant volumes of cocoa that go into making Kit Kat will open whole new possibilities for these farmers, giving them a more sustainable livelihood and the chance to plan for a better future."
Ms Lamb said she hoped the decision by Nestle, following a move to switch production of Cadbury's Dairy Milk chocolate bars to Fairtrade earlier this year, will start to "tip the balance" in cocoa trade.
David Rennie, managing director of Nestle Confectionery, said: "Nestle sells more Kit Kats in the UK than anywhere else in the world and I am delighted that following the launch of the global Cocoa Plan, Kit Kat - our leading confectionery brand - will now be Fairtrade certified in the UK and Ireland.
"UK consumers are increasingly interested in how we source and manufacture their favourite products and certifying our largest and most iconic brand is one of the ways in which we are committing to improving the lives of as many cocoa farming families as possible. Over 6,000 Ivorian farmers will benefit immediately as a result of today's announcement."
The Fairtrade mark now appears on more than 4,500 products in the UK, 15 years after it was first launched. Under the Fairtrade terms, farmers receive a guaranteed minimum price plus a premium of over £100 a tonne, which is used for business or social development products.
Trade and Development Minister Gareth Thomas welcomed the announcement, saying: "This will give thousands of Ivorian cocoa farmers better opportunities to trade their way out of poverty."