Let us imagine that a year from now the new Conservative government in Britain makes a proposal to the Spanish presidency of the Council to change the treaties on which the European Union is founded.
There are two scenarios, depending on if the Treaty of Lisbon is in force or not.
First we have to look at the circumstances if the second Irish referendum turns in a negative answer or if complications in the Czech Republic, Poland or Germany (or unforeseen events) have prevented the entry into force of the Lisbon Treaty by the time the Conservative Party forms the government in the United Kingdom.
If the Treaty of Lisbon is not in force, the UK government would demand the repatriation of powers concerning social and employment policies, as the Conservatives have promised.
According to the existing Article 48 of the Treaty on European Union (TEU) the Council would decide to consult the European Parliament and the Commission, the latter because the proposal comes from a member state and because the limited powers are European Community competences (first pillar).
After these opinions the Council could call an intergovernmental conference (IGC). This decision is procedural, so it does not require unanimity, only a simple majority (14 out of 27 member states).
What we do know, is that the treaty reform process has been ongoing since December 2000, when political agreement was reached on the Treaty of Nice. At this point in time 27 EU member states have been able to agree unanimously on the compromise Treaty of Lisbon, and 26 national parliaments have approved the amending treaty.
The national political leaders are fed up with institutional reform, and forcing a new round of negotiations would hardly meet with enthusiasm.
Many in Great Britain seem to be unaware of how isolated their country is in the European Union. I doubt that the UK would be able to rally the support of even thirteen other member states.
Even if a simple majority decided to come out in favour of an intergovernmental conference, the treaty amendments would have to be agreed by common accord (unanimity).
Things would then advance to the third hurdle: The agreed amendments would have to be ratified by all member states to enter into force.
Politically, allowing the United Kingdom to opt out of new substantial swathes of Community legislation, in addition to its existing opt-outs, contrary to the voices n many member states calling for a more “social Europe”, would further distort competition on equal terms in the internal market.
Giving in to the British demands would also saddle the European Union with an obstructionist member, bent on using its veto powers to block progress for a long time to come.
In practice, it would translate into a stop for further EU enlargement, because the Lisbon Treaty is the minimum reform required by France and Germany (too little, in my humble opinon).
Could the UK find allies during this process? I imagine that some member states might try to avert British secession because of their market orientation and intergovernmentalist attitude.
Proponents of a European foreign and security policy as well as defence might see Britain as a necessary contributor, but this is a pipe-dream because of the UK’s traditional attitude and the Tories’ basic rejection of any obligations towards its European partners.
To fulfil its election promises, the Conservative UK government would have to make a public proposal to tear up the Treaty of Nice, although in a limited fashion.
The effort would probably fail at the first hurdle, but it would be almost guaranteed to hit a brick wall at agreement time, even if the member states’ governments are famous for pusillanimity and muddling through.
Given Britain’s obstructionist record and the Conservatives’ disdainful attitude to their European partners (including leaving the EPP-ED group in the European Parliament), it is hard to believe that none of the national parliament would revolt against a ratification proposal, in the unlikely case that the process was allowed to advance that far.
Sooner or later the UK government would have to admit that it has reached a dead end. For domestic reasons it could hardly shrug it off without a show of action. Unable to deform the treaty, David Cameron and William Hague would probably feel the need to call a referendum on British EU membership.