Answer given by Mr Prodi on behalf of the Commission
The European Communities and the European Union have been established by the relevant treaties among the Member States. The treaties apply to the Member States (Article 299 of the EC Treaty). When a part of the territory of a Member State ceases to be a part of that state, e.g. because that territory becomes an independent state, the treaties will no longer apply to that territory. In other words, a newly independent region would, by the fact of its independence, become a third country with respect to the Union and the treaties would, from the day of its independence, not apply anymore on its territory.
Under article 49 of the Treaty on European Union, any European State which respects the principles set out in Article 6(1) of the Treaty on European Union may apply to become a member of the Union. An application of this type requires, if the application is accepted by the Council acting unanimously, a negotiation on an agreement between the Applicant State and the Member States on the conditions of admission and the adjustments to the treaties which such admission entails. This agreement is subject to ratification by all Member States and the Applicant State.