Mars, the US-based confectionery giant, has outlined plans to use only “sustainable” cocoa in its products by 2020.

The M&M’s-to-Snickers maker has teamed up with the Rainforest Alliance and the company said it wants the not-for-profit organization to certify 100,000 metric tonnes of cocoa annually for use in its products.

Mars will look to promote its sustainability credentials by placing a Rainforest Alliance logo on the Galaxy bars it sells in the UK and Ireland from next year.

Fiona Dawson, managing director of Mars Chocolate in the UK, said the company was “very proud” to announce the tie-up with the Rainforest Alliance.

“Not only is it our biggest brand in terms of sales in the UK, but it is also entirely chocolate,” Dawson said. “As a result it is the brand where we can make the biggest difference.”

Tensie Whelan, president of the Rainforest Alliance, said Mars’ move to use cocoa certified by the organisation in Galaxy showed “ real commitment to sustainable farming”.

“When companies with the scale and heritage of Mars show this level of leadership, the results are measurable improvements in the quality of life for cocoa farmers, their families and communities, and a cleaner, greener environment for all of us,” Whelan said.

Last month, Cadbury laid out its own plans to achieve Fairtrade certification for Cadbury Dairy Milk by the end of the summer.