What exactly is Article 50, how does it work and how does the ECJ's ruling affect things?

Following two Commons defeats of Theresa May's Brexit Withdrawal Agreement - the first by a stunning margin of 230 votes on January 15, and the second by a margin of 149 votes on March 12 - the Prime Minister is to ask the EU for a short extension to Article 50.

Read on to find out more.

What exactly is Article 50?

Article 50 of the Treaty of Lisbon gives any EU member state the right to quit unilaterally and outlines the procedure for doing so. It gives the leaving country two years to negotiate an exit deal. When the UK triggered Article 50, it was thought that once in motion it couldn't be stopped except by unanimous consent of all member states. The ECJ's ruling changes that completely.