This is the Ofgem finding that is likely to cause the energy companies the most anxiety:
This morning, the chief executive of Centrica, Sam Laidlaw, told me he "refutes totally" the idea that the 'Big Six' are a big cartel. He says the market is "vibrant" and "very competitive".
Mr Laidlaw told ITV News only 9 per cent of British Gas's 9.2 million household customers have never switched supplier and "we gain and lose more than 20,000 customers every week."
Serious allegations, strong denials. Thank goodness, some would say, that the new Competition and Markets Authority is looking into this.