Brexit legal challenge could be overturned within weeks as Government given permission to launch appeal

The High Court has ruled that MPs must vote for Britain to trigger Article 50 – but that could be overturned within weeks

The Government has been given the go-ahead to appeal the court ruling that MPs must vote before Britain can leave the EU.

That could mean that the decision – which could allow MPs to overrule Brexit entirely – could be reversed within weeks.

The Government has been given permission to take its appeal straight to the Supreme Court, the highest legal authority in the UK, and get around the need for going to the Court of Appeal.

It hasn't yet indicated that it will, and those campaigners behind the case said that they hoped that the government wouldn't. But International Trade Secretary Liam Fox said the Government is "disappointed" at the High Court decision on Article 50 adding "the Government is determined to respect the result of the referendum".

The case was seen as one of the most important constitutional cases in generations. Three senior judges including Lord Chief Justice Lord Thomas ruled that the Prime Minister can't use the royal prerogative to trigger Article 50 of the Lisbon Treaty, a move that would start the UK's exit from the European Union.

Instead, that decision must be made my parliament, the High Court ruled. That will stand unless the appeal at the Supreme Court is successful.

Unless overturned on appeal at the Supreme Court, the ruling threatens to plunge the Government's plans for Brexit into disarray as the process will have to be subject to full parliamentary control.

Government lawyers had argued that prerogative powers were a legitimate way to give effect "to the will of the people" who voted by a clear majority to leave the European Union in the June referendum.

But the Lord Chief Justice declared: "The Government does not have power under the Crown's prerogative to give notice pursuant to Article 50 for the UK to withdraw from the European Union."