ECB paper by Phoebus Athanassiou (Legal Counsel, European Central Bank)
……….Article 50 of the Lisbon Treaty explicitly makes provision for the voluntary secession of a Member State from the EU. Specifically, the exit clause provides that a Member State wishing to withdraw from the EU must inform the European Council of its intention; the Council is to produce guidelines on the basis of which a withdrawal agreement is to be negotiated with that Member State; and the Council, acting by a qualified majority and after obtaining the consent of the European Parliament, will conclude the agreement on behalf of the EU. The withdrawing Member State would cease to be bound by the treaties either from the date provided for in the withdrawal agreement or, failing that, two years after notification of its intention to withdraw. A former Member State seeking to rejoin the EU would have to follow the same admission procedure as any new candidate country……..