Cadbury is to become the first mass-market chocolate brand to adopt the Fairtrade certification mark, signalling the rising importance of ethical credentials to big business even as consumers become choosier in how they spend their money.

The confectionery group will certify 300m of its Cadbury Dairy Milk chocolate bars as well as its packaged cocoa, at a cost of £1.5m ($2.1m), by the end of summer. The company raised prices last year, partly to absorb the cost of the move to Fairtrade.