E.On chief hits back at claims of Big Six 'stranglehold" on energy He said: "We don't see the need for vertical integration, we absolutely will not cross-subsidise and we have the view that cross-subsidy should not be condoned in this marketplace." Mr Cocker admitted that E.On would struggle to compete with rivals who have bigger power generation businesses if they were to do so. If you have some players who are cross-subsidising between different parts of the business, that distorts the marketplace and will hit all of the players who don't have that capability - of which we are one. But there's many others who have the same issues. It would distort competition. In a recent research note, analysts at Credit Suisse predicted that UK power prices were likely to rise in a looming energy crunch and that "if power prices go to very high levels for a sustained period, utilities with large amounts of generation may begin to cross-subsidise their customers with generation by taking a lower margin in supply." This could "hamper those with large retail businesses," it said, identifying E.On and British Gas owner Centrica as companies that would be "net buyers on the market at times of peak demand" as they "cannot completely supply their own customers with their own generation and contracts." Mr Cocker has acknowledged the poor reputation of the Big Six and implemented a so-called "reset review" to try to improve customer service at E.On. He said he was pleased with the progress but had more to do such as making sure "we answer phone as quickly as our customers expect" and that "when our customers call in we can deal with their question first time around rather than passing them around." However, he rejected the idea of implementing a customer cash-back guarantee on such standards, such as that adopted by SSE recently, dismissing his rival's pledge as "a bit of showmanship."