Surveys across Europe show holidaymakers are suffering as shops, bars and restaurants in countries who have adopted the euro appear to be using the conversion as an excuse to round up their prices, reports The Times.

European authorities say that the reported price rises are imagined because tourists are unfamiliar with the currency. However, a survey by the German newspaper Bild am Sonntag has pointed to substantial increases in resort areas, topped by a 76 per cent increase in the price of beer in Rimini, in northeast Italy.

The complaints about Europe's price rises come a week after a poll for Credit Suisse First Boston revealed that opposition to the single currency has risen sharply in Britain, with only 35 per cent believing we should join.

A spokesperson for Britain in Europe played down the importance of the increases, saying: 'If Britain decides to join the euro, we need to learn lessons from those countries that took action to curb rounding up.

'But we should not get this problem out of proportion: the figures show that the introduction of the euro led to price rises of no more than 0.2 per cent, and prices in Britain are 15 per cent higher than the eurozone average.'