Marks & Spencer is reported to have turned the screws on suppliers as it battles to cope with sterling’s fall in value.

The retailer is attempting to renegotiate contract terms following an increase in the costs of sourcing from the Far East, Europe and South America.

One supplier told The Guardian: “It’s a constant battle to maintain agreements that were signed off before the economic crisis took a turn for the worse last year.”

But a Marks & Spencer spokeswoman denied a wide-ranging attempting to overturn contracts.

She said: “There is always a process of ongoing discussions with our suppliers about pricing. We are working hard with them to close the gap that has opened up as a consequence of the decline in the value of the pound.”

Analysts believe currency costs could add 10 per cent to Marks & Spencer’s costs this financial year.