With the coming into force of the Lisbon Treaty on 1 December, members of the European Parliament, who up to now have been "representatives of the peoples of the States brought together in the Community", become "representatives of the Union's citizens" (Art.14 TEU; cf Art.189 TEC).

This change in the status of MEPs is but one illustration of the constitutional revolution being brought about by the Lisbon Treaty.

For Lisbon, like the EU Constitution before it, establishes for the first time a European Union which is constitutionally separate from and superior to its Member States, just as the USA is separate from and superior to its 50 constituent states or as Federal Germany is in relation to its Länder.

The 27 EU members thereby lose their character as true sovereign States. Constitutionally they become more like regional states in a multinational Federation, although they still retain some of the trappings of their former sovereignty. Simultaneously 500 million Europeans becomes real rather than notional or symbolical citizens of the constitutionally new post-Lisbon European Union.

Most Europeans are unaware of these astonishing changes, for two reasons. One is that, with the exception of the Irish, they have been denied any chance of learning about and debating them in national referendums. The other is that the terms "European Union", "EU citizen" and "EU citizenship" remain the same before and after Lisbon, although Lisbon changes their constitutional content fundamentally.

The Lisbon Treaty therefore is a constitutional revolution by stealth.

The EU Constitution, which the peoples of France and the Netherlands rejected in 2005, sought to establish a new European Union in the constitutional form of a Federation directly. Its first article stated: "This Constitution establishes the European Union". That would clearly have been a European Union with a different constitutional basis from the EU that had been set up by the Maastricht Treaty 13 years before.

A constitutionally new Union

Lisbon brings a constitutionally new Union into being indirectly rather than directly, by amending the two existing Treaties instead of replacing them entirely, as the earlier Constitutional Treaty had sought to do.

Thus Lisbon states: "The Union shall be founded on the present Treaty" - viz. the Treaty on European Union -"and on the Treaty on the Functioning of the Union." These two Treaties together then become the Constitution of the post-Lisbon European Union. A new Union is being "constituted", although the word "Constitution" is not used.

What we call the "European Union" pre-Lisbon is the descriptive term for the totality of legal relations between its 27 Member States and their peoples. This encompasses the European Community, which had legal personality, made supranational laws and had various State-like features, as well as the Member States cooperating together on the basis of retained sovereignty in foreign policy and defence and in crime and justice matters.

Lisbon changes this situation fundamentally by giving the post-Lisbon Union the constitutional form of a true supranational Federation, in other words a State.

The EU would still lack some powers of a fully developed Federation, the most obvious one being the power to force its Member States to go to war against their will. It would possess most of the powers of statehood however, although it has nothing like the tax and spending levels of its constituent Member States.

Three steps to a federal-style constitution

Lisbon's constitutional revolution takes place in three interconnected steps. Firstly, the Treaty establishes a European Union with legal personality and a fully independent corporate existence in all Union areas for the first time (Arts.1 and 47 TEU).

This enables the post-Lisbon Union to function as a State vis-a-vis other States externally, and in relation to its own citizens internally

Secondly, Lisbon abolishes the European Community which goes back to the Treaty of Rome and which makes European laws at present, and transfers the Community's powers and institutions to the new Union, so that it is the post-Lisbon Union, not the Community, which will make supranational European laws henceforth (Art.1 TEU).

It also transfers to the EU the "intergovernmental" powers over crime, justice and home affairs, as well as foreign policy and security, which at present are not covered by European law-making, leaving only aspects of the Common Foreign, Security and Defence Policy outside the scope of its supranational powers. The Treaty thereby give a unified constitutional structure to the post-Lisbon Union.

Thirdly, Lisbon then makes 500 million Europeans into real citizens of the new Federal-style Union which the Treaty establishes (Arts.9 TEU and 20 TFEU). Instead of EU citizenship "complementing" national citizenship, as under the present Maastricht Treaty-based EU (Art.17 TEC), which makes such citizenship essentially symbolical, Lisbon provides that EU citizenship shall be "additional to" national citizenship.

This is a real dual citizenship - not of two different States, but of two different levels of one State. One can only be a citizen of a State and all States must have citizens.

Dual citizenship like that provided for in Lisbon is normal in classical Federations which have been established from the bottom up by constituent states surrendering their sovereignty to a superior federal entity, in contrast to federations that have come into being "top-down" by unitary states adopting federal form.

Examples of the former are the USA, 19th Century Germany, Switzerland, Canada, Australia. Lisbon would confer a threefold citizenship on citizens of Federal Germany's Länder.

Being a citizen means that one must obey the law and give loyalty to the authority of the State one is a citizen of - in the case of classical Federations, of the two state levels, the federal and the regional or provincial.

In the post-Lisbon EU, the rights and duties attaching to citizenship of the Union will be superior to those attaching to one's national citizenship in any case of conflict between the two, because of the superiority of EU law over national law and Constitutions (Declaration No 17 concerning Primacy).

The EU will be constitutionally superior even though the powers of the new Union come from its Member States in accordance with the "principle of conferral" (Art.5 TEU). Where else after all could it derive its powers from?

This is so even though the Member States retain their national Constitutions. The local states of the USA retain their different state Constitutions and citizenships, even though both are subordinate to the US Federal Constitution in any case of conflict between the two.

The tenth amendment to the US Constitution alludes to the principle of conferral when it lays down that powers not delegated to the US Federation"are reserved to the states respectively, or to the people". Likewise it is normal for the Constitutions of classical Federations to provide for a right of withdrawal for their constituent states, just as the Lisbon Treaty does (Art.50 TEU).

An alternative source of democratic legitimacy

Under Lisbon population size will in turn become the primary basis for EU law-making, as in any State with a common citizenry. This will happen after 2014, when the Treaty provision comes into force that EU laws will be made by 55% of Member States as long as they represent 65% of the total population of the Union.

Lisbon provides an alternative source of democratic legitimacy which challenges the right of national governments to be the representatives of their electorates in the EU. The amended Treaty provides: "The functioning of the Union shall be founded on representative democracy. Citizens are directly represented at Union level in the European Parliament. Member States are represented in the European Council by their Heads of State or Government and in the Council by their governments..." (Art.10 TEU).

Contrast this with what is stated to be the foundation of the present Mastricht Treaty-based EU (Art.6 TEU): "The Union is founded on the principles of liberty, democracy, respect for human rights and fundamental freedoms, and the rule of law, principles which are common to the Member States."

The constitutional structure of the post-Lisbon EU is completed by the provision which turns the European Council of Prime Ministers and Presidents into an "institution" of the new Union (Art.13 TEU), so that its acts or its failing to act would, like those of the other Union institutions, be subject to legal review by the EU Court of Justice.

Constitutionally speaking, the summit meetings of the European Council will henceforth no longer be "intergovernmental" gatherings outside supranational European structures, as they have been up to now. The European Council will in effect be the Cabinet Government of the post-Lisbon Union.

Its individual members will be constitutionally obliged to represent the Union to their Member States as well as their Member States to the Union, with the former function imposing primacy of obligation in any case of conflict or tension between the two.

One doubts if all the Heads of State or Government themselves appreciate this!

As regards the State authority of the post-Lisbon Union, this will be embodied in the Union's own executive, legislative and judicial institutions: the European Council, Council of Ministers, Commission, Parliament and Court of Justice.

It will be embodied also in the Member States and their authorities as they implement and apply EU law and interpret and apply national law in conformity with Union law. Member States will be constitutionally required to do this under the Lisbon Treaty. Thus EU "State authorities" as represented for example by EU soldiers and policemen patrolling our streets in EU uniforms, will not be needed as such.

Although the Lisbon Treaty has given the EU a Federal-style Constitution without most people noticing, there is no European people or"demos" which could give democratic legitimacy to the institutions it establishes and make people identify with these as they do with the institutions of their home countries.

This is the core problem of the EU integration project. Lisbon in effect has made the EU's democratic deficit worse.

It is hard to imagine that this will not make struggles to reestablish national independence and democracy and to repatriate supranational powers back to the Member States the central issue of EU politics in the years and decades ahead.

The writer is President of the Foundation for EU Democracy, Brussels, and Director of the National Platform EU Research and Information Centre, Dublin.