Vickie Sheriff, Director of Campaigns and Communications at Which? said:
“If energy companies have failed to tell the whole truth about their profits, then customers will rightly be angry. The Energy Secretary and the regulators must investigate these claims.
“This is the last chance saloon for the energy industry. Following the market investigation, energy companies now must prove they are taking action to genuinely engage with their customers stuck on the worst deals. The Government and the regulator must be ready to act if energy companies fail to deliver.”