The ‘Luxembourg compromise’ of January 1966 applies where qualified majority voting is used in the Council of the European Union. A loose arrangement which was never recognised by the European Commission or the European Court of Justice, the Luxembourg Compromise effectively extended the life of the national veto beyond the transitional period allowed in the Treaties of Rome. Its genesis was the impasse known as the ‘empty chair crisis’, when France boycotted Council meetings for the last six months of 1965 in protest against bureaucratic supranationalism and the advent of qualified majority voting, thereby immobilising the Community. Under the Luxembourg Compromise, any decision which affected ‘a very important national interest’ would be deferred until a unanimously acceptable solution could be found, regardless of whether the Treaty prescribed majority voting. There were various interpretations of what counted as a vital interest and of the situation that would arise if agreement could not be reached, but the practical effect of the Compromise was to paralyse Community decision-making for the next 17 years.
If the Luxembourg Compromise had continued in use, the Single European Market would not have come into existence and the Maastricht and Amsterdam Treaties would not even have reached the drafting stage. It remains, some say, as a theoretical weapon of last resort, but most national interests of importance are covered by the unanimity principle or by opt-outs, and the Community's affairs are now so extensive that the invocation of the Compromise on an issue of middling significance would invite painful retaliation. For practical purposes, therefore, the Compromise has been consigned to history. However, as recently as 19 June 2003 the French government invoked its ‘vital interests’ to block a qualified majority vote on agricultural policy in a Council meeting of farm ministers.