Article 50 of the Treaty on European Union

Article 50 of the Treaty on European Union is a part of European Union law that sets out the process by which member states may withdraw from the European Union. Its use became extensively debated after the referendum held in the United Kingdom on 23 June 2016 in which a majority of those voting favoured the United Kingdom's withdrawal from the European Union.

Once article 50 is triggered, there is a two-year time limit to complete negotiations. If negotiations fail to reach agreement, the member state leaves with nothing. This process is generally accepted to leave a seceding member without any bargaining power in negotiations, because the costs of having no trade treaty would be proportionally far greater to the seceding individual state than the remaining EU bloc.

Article 49A of the Treaty of Lisbon, which came into force on 1 December 2009, introduced for the first time a procedure for a member state to withdraw voluntarily from the EU. This is specified in Article 50 of the Treaty on European Union, which states that:

Article 50 of the Treaty on European Union provides that: "Any Member State may decide to withdraw from the Union in accordance with its own constitutional requirements." Once a member state has notified the European Council of its intent to leave the EU, a period begins during which a leaving agreement is negotiated setting out the arrangements for the withdrawal and outlining the country's future relationship with the Union. A withdrawal agreement would then be negotiated between the Union and that State.

Coverage of the issue with respect to the United Kingdom in The Guardian includes an explanation as to Article 50 and how it would be invoked. "...there seems to be no immediate legal means out of the stalemate. It is entirely up to the departing member state to trigger article 50, by issuing formal notification of intention to leave: no one, in Brussels, Berlin or Paris, can force it to. But equally, there is nothing in article 50 that obliges the EU to start talks – including the informal talks the Brexit leaders want – before formal notification has been made. "There is no mechanism to compel a state to withdraw from the European Union," said Kenneth Armstrong, professor of European law at Cambridge University. ... "The notification of article 50 is a formal act and has to be done by the British government to the European council," an EU official told Reuters."

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