Gordon Brown has warned retailers he will force them to cut down on plastic bag use if they do not act voluntarily.

Writing in the Daily Mail, he told stores that "If government compulsion is needed to make the change, we will take the necessary steps."

Campaigners say plastic bags, which take an estimated 1,000 years to decay, damage the environment.

Marks and Spencer has already announced that it will charge food shoppers 5p for each bag from 6 May.

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The move follows a trial at 50 of its outlets in Northern Ireland and south-west England, which resulted in demand for polythene bags falling by more than 70%.

'Strong action'

Mr Brown praised the chain - which says the money raised will go to environmental charities - as well as Ikea, which stopped providing single-use plastic bags from its branches in July 2007.

But he insisted that, if other stores did not follow suit, the government would be "ready to do what it can".

"We do not take such steps lightly - but the damage that single-use plastic bags inflict on the environment is such that strong action must be taken," he said.

Ideally, he said, any scheme to cut down on their use would also secure funds for environmental organisations.

Full article here.