Phillips-Davies told the newspaper that the CMA had failed to prove its case, echoing comments made by Eon chief executive Tony Cocker at the Utility Week Congress last year.
Phillips-Davies told the Financial Times: “ have completely failed to substantiate the evidence they have got and I think they have overestimated what they have done.”
Asked by the newspaper whether SSE would consider legal action if the CMA pressed ahead with its proposal for a price cap for customers on standard variable tariffs, Phillips-Davies said: “We would have to think about that.”
The CMA is due to make its final recommendations in June 2016.