High Court hears Brexit challenge

The High Court will today hear details of a first legal challenge to Britain's exit from the European Union.

Lawyers representing a British citizen will argue that the government needs the approval of Parliament before it can trigger Article 50 of the Lisbon Treaty and formally set in motion the two-year process for Brexit. They will say that the referendum result is 'advisory'.

Lawyers representing expats in France are expected to join the case, brought by the law firm Edwin Coe.

The challenge comes after Brexit minister David Davis said that the formal Brexit process could start as early as the end of the year.

Today's hearing, in front of judges Sir Brian Leveson and Mr Justice Cranston, will deal mainly with administrative matters - and is also set to hear details of two other challenges to the referendum result.

One, brought by the law firm Mischcon de Reya on behalf of a group of unnamed businesses, argues that Article 50 can only be triggered following an Act of Parliament. The other argues that the process must be backed by legislation.

Government lawyers have said that invoking Article 50 does not require a Parliamentary vote, but Prime Minister Theresa May has previously insisted that she would not begin the formal process until a 'UK approach and objectives' for talks with Europe are agreed.

The judges will decide if all the cases should be combined. A full hearing is not expected until autumn.