The case was heard by all 11 justices over four days from 5 to 8 December after the Secretary of State for Exiting the European Union, David Davis, appealed the High Court’s ruling that government does not have the power to trigger Article 50 without gaining parliamentary approval and a vote from MPs first.

The judges rejected the case by a majority of eight to three.

The judgment rules: 'The Supreme Court considers that the terms of the ECA, which gave effect to the UK’s membership of the EU, are inconsistent with the exercise by ministers of any power to withdraw from the EU Treaties without authorisation by a prior Act of Parliament.'

The judgment deemed that due to the withdrawal from the EU removing some exisiting rights of UK residents, the government is unable to withdraw from EU treaties without first consulting Parliament, but the court ruled that Scottish Parliament and Welsh and Northern Ireland assemblies did not need a say.

The decision will not overturn the referendum result but makes the course for leaving the EU lawful.

A government spokesperson said: 'The British people voted to leave the EU, and the government will deliver on their verdict – triggering Article 50, as planned, by the end of March. Today’s ruling does nothing to change that.

'It’s important to remember that Parliament backed the referendum by a margin of 6 to 1 and has already indicated its support for getting on with the process of exit to the timetable we have set out. We respect the Supreme Court’s decision, and will set out our next steps to Parliament shortly.'

Lord Chancellor, Elizabeth Truss said: 'Our independent judiciary is the cornerstone of the rule of law and is vital to our constitution and our freedoms. The reputation of our judiciary is unrivalled the world over, and our Supreme Court justices are people of integrity and impartiality.

'While we may not always agree with judgments, it is a fundamental part of any thriving democracy that legal process is followed. The government has been clear that it will respect the decision of the court.'

Prime Minister Theresa May previously announced that she would trigger Article 50, which formally notifies the EU of the UK’s decision to leave, by the end of March 2017 and on 17 January 2017 set out her 12-point plan to prepare the UK to leave the EU.

R (on the application of Miller and another) (Respondents) v Secretary of State for Exiting the European Union (Appellant) is available here.