If its 6% I would be pleasantly surprised, said CPI director of business affairs, Graham Barnard.

Any higher and Barnard said this would lead to electricity firms profiting as a result of further price increases on industry overheads.

Energy minister Steven Timms said that household electricity bills may rise by 3% and industry sectors may have to pay 6% more.

Business leaders have said that the European-wide emissions trading scheme, starting in 2005, would make them uncompetitive.

Industry has to compete internationally, and unlike the electricity groups it cannot just pass on costs to its customers, Barnard said.