Section 50 is the article within the Lisbon Treaty that covers any Member State of the EU wishing to withdraw from the union. In his resignation speech following the surprise result of the Brexit referendum, David Cameron clearly stated that he would not invoke Article 50 but would leave that to his successor.

Following the result, EU leaders called upon the UK to immediately invoke Section 50 so negotiations could begin and avoid continuing uncertainty until a deal for the UK to leave is agreed. Article 50 can only come into effect when the UK decides to invoke it – the EU cannot force them to do this.

Article 50 is the road map for a country leaving the European Union and it does not involve trade deals. Instead, its focus is primarily on issues like determining the work permit and social benefits status of the almost 3 million British people living in the EU and Europeans based in the UK. Once invoked, the UK and the remaining 27 member states have 2 years to disentangle from each other and tie off any loose ends. If this is not achieved within that time frame, the deadline can be extended through unanimous agreement from both sides; if such a situation arose, it is probable deadline extensions would be agreed.

Negotiations are likely to be tough and potentially punitive for the UK in order to discourage similar actions within other member states which would ultimately undermine the entire European Union project. If the UK were to receive an attractive deal, this might embolden populist politicians across the EU to seek similar referendums in their own countries.

In the meantime, all existing trade deals will remain in place until after Article 50 negotiations are complete. However, upon their completion, each will cease to exist overnight. The UK will be forced to renegotiate a single trade deal with the remaining member states, including Ireland. The UK will also be forced to renegotiate deals with 60 other countries with which it had agreements while a member of the EU.