"The process for the UK leaving the EU is set out in article 50 of the Treaty of Lisbon. Once the UK tells the European Council it wants to leave, there is a two-year deadline to negotiate the divorce settlement. This will be a challenging timetable as all national governments and the European Parliament will need to be involved.
"Unless the two-year deadline is extended by agreement, the EU treaties and EU Regulations will cease to apply in the UK. But most EU law will continue to apply until it’s reviewed by Parliament because it is in the form of UK statutory instruments (of which there are more than 100,000).
"It will not be a simple process to unpick 40 years of the mixing of UK and EU law. Businesses and local authorities alike will need to tread carefully through this maze in the next few years."