The decision by Germany's economics ministry to override the national cartel office and approve energy company E.ON's intention to acquire a majority shareholding in Ruhrgas is certain to face a legal challenge.

Aribert Peters of Bund der Energieverbraucher (the Association of Energy Consumers), said the deal is unlawful and must be challenged in court because it has serious disadvantages for consumers. He said Europe's energy firms are unaninimous in their criticism of the deal hatched between E.ON and the German government. He listed RWE, ENBW, Bewag, Centrica, Fortum Oel among those which considered the deal uncompetitive.