Today’s decision follows the Competition and Markets Authority’s (CMA) initial Phase 1 investigation which found that the deal could reduce competition, potentially leading to higher prices for some bill payers.

SSE and Npower did not offer measures to address the CMA’s concerns, and so it has referred the merger for a more in-depth, Phase 2 investigation.

A decision on the merger will now be made by a group of independent panel members supported by a case team of CMA staff. The deadline for the final report is 22 October.