Swiss cheese suppliers have warned that the price of cheeses such as Gruyère and Emmental will have to go up because of an increasingly unfavourable exchange rate with sterling.

The Swiss franc has been exceptionally strong recently, with sterling losing 21% of its value against it in the past three months.

Switzerland Cheese Marketing said the time had come for them to increase their sales prices. "We are confident British consumers will expect to pay a little more for our unique products," said Maurice Johnson, head of the organisation in the UK.

"We are not increasing our prices to improve our cheesemakers' or exporters' profits, but to limit current losses."

Although exporters can put up their wholesale prices to retailers, it is up to individual retailers to decide whether to pass those rises on to consumers in the form of higher retail prices.