But there are concerns that the merger would make it harder to regulate Northern. Hence the desire of Stephen Littlechild, head of Offer, the industry regulator, to see Northern ring-fenced within Trafalgar or even - controversially - refloated to have outside minority shareholders.
Of wider concern is the future shape of the entire electricity distribution industry. The Government's "golden shares" in the 12 regional electricity companies - mechanisms protecting them from takeover - expire on 31 March. After that there is likely tobe a free-for-all, with predators, British and foreign, picking off the weakest RECs, others merging with one another for protection, others again perhaps forming alliances with water utilities in the same region, and who knows what else. There are implications for electricity users, both domestic and business.
If the Government wants to have a say in the shape of the industry, it needs to act now, referring not just Northern, but the whole industry to the MMC. If it lets one deal through, the harder it will be to act on others which are bound to follow.
In the first five years of privatisation the lion's share of the fruits have gone to shareholders. Northern's share price, for example, has quadrupled. Electricity consumers deserve a better deal in the next five years. Over to you, Mr Heseltine.