Customers desert SSE despite energy price freeze

But SSE has already admitted it will struggle to do so because it has bought most of its energy further in advance than normal, locking customers in to higher prices.

Will Morris, SSE group managing director for retail, attempted to shrug off the losses.

"We operate in a very competitive market and, as you would expect, different supply companies take different approaches and have different propositions," he said.

"There are some short-term offers available at the moment, which a limited number of customers can benefit from. These offers will come and go, but SSE is offering all customers the long-term certainty that its standard prices will not go up until at least 2016.

"Things can change very quickly in energy; this is an unprecedented long-term commitment and it should be judged over the long term."

SSE said that its financial performance remained on track for full-year earnings to be in line with or slightly greater than last year's and for a dividend increase at least in line with inflation.

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