A Conservative government would tackle Britain’s ‘addiction to debt’, according to shadow chancellor George Osborne.

He was speaking as he unveiled a plan to give the Office of Fair Trading powers to clamp down on store cards which charge 'excessive' rates of interest. The Tories are also suggesting a seven-day cooling off period before people can start using their cards.

At a GMTV interview the shadow chancellor said: “We've got a big problem in Britain, we’re addicted to debt, and we are seeing the consequences of that as the credit crunch hits, and everyone is finding it more and more difficult with the rising cost of living.

“I think the role of the next Conservative government is to stop Britain’s addiction to debt, and make sure when we next have a financial crisis or economic problem, that we are much better prepared than we are at the moment.”

People in the UK owe £2.2billion on store cards, the Conservatives said, with the number of accounts having almost doubled from seven million to 13.4million in the last five years. A party spokesman quoted the Competition Commission as saying some store card rates were ‘above competitive levels’.

He added: “Excessively high store card interest rates are costing the British public over £55million per year.”

Under Mr Osborne's plans, the Office of Fair Trading (OFT) would be given powers to define ‘excessive’, drawing on factors such as mainstream interest rates on credit cards market.