It is as much a part of Christmas as crackers and turkey but the Cadbury Roses tin is to be ditched after 70 years to be replaced by a new "greener" square cardboard box.

The move, which the chocolate maker is trialling with Tesco, is part of wider efforts by big-name companies to jump on the green bandwagon in the run-up to Christmas.

Amazon, the online group, has already announced plans to replace plastic packaging on some toys and other items with cardboard boxes.

The new Roses boxes holds the same quantity of chocolates - 975g - as the tins. The recommended retail price, of £8.31 is also the same. Replacing the tins, which were introduced in 1938, will cut packaging by 45 per cent per pack and save more than 200 tonnes of steel each year, Cadbury said.

The group said the move would help it to "meet shoppers' ethical concerns" while also boosting sales.

The Committee of Advertising Practice recently tightened its code around "green marketing" after it emerged that many businesses were issuing exaggerated claims about the environmental credentials of their products.

The trend, which follows a boom in the market for green goods, has become known as "greenwash." The watchdog has reminded companies that claims about specific environmental credentials should not be used without evidence to back them up.

The move by Cadbury to ditch its famous Roses packaging, which still feature in many homes as hold-alls for stray sewing kits or cake tins, has emerged as the British chocolate maker prepares for an expected hostile bid from its stalker, Kraft, the giant American food company.

Under Takeover Panel rules Kraft, which has been pursuing the Dairy Milk and Creme Eggs maker since September in a £10.6 billion takeover battle, must formally bid by 5pm next Monday or walk away for six months.

Kraft is believed to have obtained $9 billion (£5.5 billion) of financing for its part-share, part-cash offer from nine banks.

The group offered 745p a share for its target in September - when it was rebuffed by Cadbury. Bank of America Merrill Lynch, issued a note last week saying there was a 75 per cent chance that Kraft would go hostile with a bid of 780p.

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