WOULD you like a side order of conscience? It’s not a question McDonald’s staff usually ask, but the fast-food giant is hoping to boost its image and even attract the odd ethical consumer by signing Britain’s biggest fair-trade restaurant deal.

UK bosses will this week approve a £1m deal to buy coffee from South and Central American farm co-operatives, certified by the Rainforest Alliance, an independent fair-trade watchdog.

Some 3,000 farmers and their families in 15 countries will receive £900,000 for 800 tonnes of coffee at market rates, plus an extra 5.5p for every 1lb sold. The premium will total £100,000 a year.

McDonald’s hopes its first step into the £5 billion ethical-food market will help to change the perception that it is a low-wage, low-quality food firm. Steve Easterbrook, its UK boss, said: “We are a modern, progressive company. We offer our customers great-tasting coffee that also benefits coffee growers.”

Although the average premium per farming family works out at £33 — the cost of just a few family meals at McDonald’s — Easterbrook said: “It encourages long-term sustainability.”

Tensie Whelan at the Rainforest Alliance added: “In some countries, notably Colombia where farms are small, this sum doubles a farmer’s annual income.”

McDonald’s is launching a £500,000 advertising campaign to promote its new coffee — and its new-found ethical credentials. Radio and poster ads will urge customers to buy their latte or cappuccino from McDonald’s because “our coffee doesn’t cost the earth”.

Consumer groups praise McDonald’s for adopting fair trade, but critics argue that it has failed to address issues surrounding the fat and sugar content of its foods.

Easterbrook recently announced that the firm was going “back to basics and back to burgers” after new products, notably salads, flopped. The firm even introduced a promotional Bigger Big Mac.

Easterbrook said: “As we re-examine our global trading deals, we are also making menu and ingredients changes at home. Is there more we can do? Yes, of course. And we will continue to work on that.”

McDonald’s sells 113,000 cups of coffee in its 1,200 restaurants in Britain every day. McDonald’s outlets across Europe will follow the UK and switch to fair-trade coffee later this year in a £50m deal.