It has been argued that there is no provision in any European Union treaty for an exit from the Eurozone. Moreover, it has been argued, the Treaties make it clear that the process of
monetary union was intended to be "irreversible" and "irrevocable." Although an explicit provision for an exit option does not exist, many experts and politicians in Europe have suggested that an option to leave the Eurozone should be included in the relevant treaties. Other analysts have submitted that there are basically three ways of exiting the Eurozone: by leaving and subsequently rejoining the EU, whereby a renewed membership in the European Union would be possible only when economic convergence had been achieved; through a Treaty amendment; or through a
European Council decision. The amendment would involve an extension of Article 50 of the
European Treaty that would set out the process for exiting the euro. A decision by the European Council would "probably" have to be
unanimous and "with the consent of the
European Parliament." It would state that a
Eurozone member-state "will no longer be part of the Eurozone" and will become a member-state "with a
derogation", by withdrawing the
Council's earlier decision for that state's entry into the Eurozone. Article 139 regulates the terms of this "derogation": Member States in respect of which the Council has not decided that they fulfil the necessary conditions for the adoption of the euro shall hereinafter be referred to as 'Member States with a derogation'. The competence of the council to retract its earlier decision would "possibly" invoke the argument that a given competence to decide on a matter always includes the competence to retract that decision. On the issue of leaving the Eurozone, the
European Commission has stated that "[t]he irrevocability of membership in the euro area is an integral part of the Treaty framework and the Commission, as a guardian of the EU Treaties, intends to fully respect [that irrevocability]." The
European Central Bank, responding to a question by a
Member of the European Parliament, has stated that an exit is not allowed under the Treaties.
Withdrawal from the European Union If a state leaves the European Union,
Article 50 of the Treaty on European Union says that "Treaties shall cease to apply to the State in question". If the state has been using the euro as its currency then, rather than form a new domestic currency, it might continue to use the euro unilaterally as Montenegro does or by way of a monetary agreement with the EU as Andorra does without being a member of the EU. ==Potential operational process==