Electricity bills in Britain have increased eight times faster than in some other European countries, according to analysts.

Energy unit prices in Britain have risen by 15% for electricity and 27% for gas in the 12 months to October 2008, according to Energy Advice, an international energy-price consultancy.

In contrast, German energy users have seen their electricity bills rise by only 1.7%, though gas prices in Germany have gone up by 20%.

In France, where the govern- ment regulates the energy market, bills rose by 5.5% for electricity and 9% for gas.

The figures raise concerns that energy giants such as Germany’s RWE, which owns Npower in Britain, and France’s EDF are fleecing British customers while protecting customers in their home countries. Eon, another energy supplier, is also based in Germany.

Ed Mayo, chief executive of the watchdog Consumer Focus, said: “The UK energy consumer is being clobbered faster and harder than those in Europe.

“Other countries may be doing more to keep their prices down and we should learn from them. The UK has a relatively free market, but the freedom to cut prices in the early years now seems to be the freedom to raise prices with impunity."

The figures echo similar concerns raised last week by the Paris-based Organisation for Economic Co-operation and Development. It said Britain’s energy bills grew at the fastest rate among all European countries except for Norway over the past 12 months.

It was also revealed last week that energy suppliers were sitting on £225m of customers’ cash because of direct-debit overpayments. Almost 6m UK households are in credit to their gas supplier by an average £79 or £449m in total, according to the comparison firm Moneysupermarket.com.

However, there are almost 2m households in debt to suppliers to the tune of nearly £224m — an average of £126 per customer.

Moneysupermarket is urging energy customers to find out if they are overpaying and to claim back the money.

Scott Byrom, who is the utilities manager at Moneysupermarket, said: “Almost four-fifths of consumers have made no attempt to ask for their money back from providers.”

You should bear in mind, however, that direct-debit tariffs are designed so that customers overpay during the summer, when energy demand is low, and underpay during the winter when demand increases. The idea is that by the end of an annual cycle, there is no debt. This means you should only claim back if you find you are consistently left with money owed at the end of each 12-month period.

A good way to make sure you are paying the correct amount is to contact your supplier to report meter readings regularly.