Article 50
From ACT Wiki
European Union - Brexit
'Article 50' refers to Article 50 of the Lisbon Treaty of 2007, which updated the constitutional arrangements of the European Union (EU).
Article 50 outlines a procedure and two-year timetable for negotiation for member states which decide to withdraw from the EU.
It is generally considered that the two-year period will start when the member withdrawing - for example the UK - serves a formal notification of its decision and intention to withdraw.
The notification is often described as 'triggering' Article 50.