European Central Bank president Mario Draghi today told the French parliament, the Assemblée Nationale, that the transfer of powers from the national to European level would, in the case of banking union, "best protect the vital interests of euro area citizens".

He said that should be the ultimate criterion in the debate over "what responsibilities need to be shared at the European level, and what not, to make European Monetary Union function effectively".

Banking union, Draghi said, is however