The Government’s long search for a private investor in new nuclear power stations has finally borne fruit — with an investor, EDF, that is 80 per cent state-owned.

The state in question happens to be France. This is not in itself ominous. On the contrary, it is one of the chief merits of a £12.4 billion deal that should eventually deliver urgently needed generating capacity, significant cuts in Britain’s carbon output and diminished reliance on Russian gas. As importantly, it will bring EDF’s unmatched expertise to the delicate and highly specialised task of refurbishing Britain’s ageing nuclear infrastructure.

Small wonder that Gordon Brown and John Hutton, the Business Secretary, were eager yesterday to trumpet the virtues of EDF’s purchase of British Energy, the country’s sole nuclear generator.

Britain needs new nuclear power stations. Its existing inventory of eight stations with a total of fifteen reactors must be decommissioned between 2014 and 2035. They provide nearly a fifth of the country’s electricity supply, which cannot be replaced quickly or affordably enough with power from renewable sources, or cleanly enough by building new fossil-fuel-powered stations: any increase in the proportion of demand met by oil, gas or coal would without question mean breaking pledges to shrink the national carbon footprint by 2020.

The Government recognised this under Tony Blair and set out its nuclear vision in a White Paper in January. That vision was based on securing outside investors — but precedents for private sector involvement in nuclear generation without large-scale public subsidy were non-existent even in the US. And when a deal with EDF was first rumoured in July, it fell through.To have revived the deal, by persuading EDF to raise its bid for British Energy by 9 per cent, is a considerable achievement — hence Mr Hutton’s insistence yesterday that there was simply no bad news to report along with the good.

Would that this were true. In fact, the structure of this deal says much about the limits of nuclear power’s appeal to the private sector. EDF has agreed to meet all nuclear waste management and decommissioning costs associated with any new plants it builds in Britain. But it will not have to pay for inherited waste and decommissioning work at the sites that it is buying. That cost will fall to the taxpayer. Nor will it confront many planning hurdles: the single most valuable asset that EDF is buying is the right to build new reactors on existing nuclear sites.

Finally, EDF is not, of course, a private concern. This matters little to UK plc since the French giant operates abroad on strictly commercial terms and is paying handsomely for British Energy. But it is significant. If the only serious bidder for Britain’s nuclear crown jewels acquired its knowhow and market dominance through decades of state subsidy, the chances of a genuinely investor-led future for the nuclear industry must be considered slim.

Mr Hutton and his successors must find ways to strengthen the nuclear argument for investors, and the courage to be honest with taxpayers about their share of the cost of nuclear power. They must also ensure that consumers are not exploited through rising prices as Britain’s big six energy suppliers consume the last of its independent energy producers.

The big six already control 99 per cent of Britain’s electricity supply. After this deal, they will control 74 per cent of the country’s generation as well, buying wholesale power increasingly from themselves and each other at the expense of genuine competition. EDF has helped to secure Britain’s future energy supply, but at a price.