A plan to create a single euro zone banking supervisor is illegal, according to a secret legal opinion for EU finance ministers that deals a further blow to a reform deemed vital to solving the bloc’s debt crisis. The legal service concludes that without altering EU treaties it would be impossible to give a bank supervision board within the ECB any formal decision-making powers as suggested in the blueprint drawn up by the European Commission. Those non-euro zone countries that want to opt into the bank supervision regime would also be legally unable to vote on any ECB decisions — a key demand of countries such as ... (full story)