[JURIST] The UK Supreme Court [official website] heard an argument [transcript, PDF] on Wednesday that the referendum vote to leave the EU is not legally binding. The appeal of last month’s ruling [JURIST report] argued that only Parliament has the authority to trigger the UK’s exit from the EU. Lawyer David Pannick argued that Parliament had not created the 2015 Referendum Act [text] to be legally binding. The Act did not specify how Article 50 [materials] would be invoked if the referendum were to pass. Pannick argued that because invoking Article 50 would nullify the European Communities Act of 1972 [text] which made the UK a member of the EU, only Parliament can initiate the UK’s exit.

A majority of British citizens voted in a referendum to leave the EU. The vote, an extension of British discontent with the EU, defied the suggestions of economists and British leaders, leading to the resignation of Prime minister David Cameron [JURIST report]. The implications of this move extend beyond just immigration, though, as many believe this separation will negatively affect the British economy, which will likely be cut off from the EU’s single market unless an agreement between the two can be reached. While the vote has fallen in favor of departure, no legal changes have taken place yet [Guardian report], as Britain must take further steps to confirm its separation. The EU has set out a mechanism for leaving in Article 50 of the Lisbon Treaty, where a member state “may decide to withdraw from the union in accordance with its own constitutional requirements,” and “must notify the European council of its intention.” Under Article 50, a member country can only be removed from the EU two years after notification. While Britain might bypass this process through repeal of the European Communities Act of 1972, it is believed that this would make coming to a preferential trade agreement with the EU more difficult.