Brexit challenge ruling to be made 'as quickly as possible'

Theresa May has said she will trigger Article 50 by the end of March next year. Credit: Reuters

High Court judges ruling on whether Britain can leave the EU without it going through Parliament first say they aim to make their decision "as quickly as possible".

The historic Brexit legal challenge is in the final of a three-day hearing.

Concerned individuals and a crowd-funded anti-Brexit People's Challenge are calling for parliamentary approval from MPs before the prime minister can trigger Article 50.

A number of applicants have challenged Theresa May's strategy for Brexit in what has been described as one of the most important constitutional cases in generations.

Campaigners argue that the prime minister has no legal power to trigger Article 50 of the Lisbon Treaty to leave the European Union without the prior authorisation of Parliament.

Mrs May announced at the Conservative Party conference that she intends doing so by the end of March 2017.

Lawyers told the court that the Government lacks legal power to use the royal prerogative to notify Article 50.

Government lawyers say that if the challenge succeeds, the government "could not give effect to the will and decision of the people, as clearly expressed in the referendum, to withdraw from the EU without further primary legislation".

Because of the urgency and constitutional importance of the case, any appeal is expected to be heard by the Supreme Court, the highest court in the land, before the end of the year.