SSE lost an appeal today over allegations the firm tricked customers into switching from their existing energy firm. The company was found guilty on two counts out of seven charges at Guildford Crown Court in May 2011 and now its appeal has been thrown out.

SSE said it was “very disappointed” with the result of the case. Responding to the failed appeal Audrey Gallacher, director of energy at Consumer Focus said: “This is an important judgement for consumers and hats off to Surrey Trading Standards for its persistence and dogged pursuit of SSE through the courts.

“Today’s guilty verdict shows this wasn’t the action of rogue salespeople but the failure of a whole system which was bound to mislead consumers… It shouldn’t take legal action from Trading Standards to make one of our biggest energy suppliers play fair with customers.”

According to the watchdog’s research more than nine out of ten people who have bought energy products on the door would never do so again. E.ON is now the only firm that hasn’t officially stopped the practice of door-to-door sales.

Currently three of the Big Six suppliers, Scottish Power, SSE and npower are being investigated by Ofgem about whether their previous door-step sales practices have broken the rules.