PM Theresa May and the UK’s Executive branch have been handed a temporary setback in the march towards Brexit as the Supreme Court rules only Parliament has the power to trigger the necessary clause to take the country out of Europe.

By a decision of eight to three, the court agreed with petitioners that Parliament has to vote on the issue, to agree to trigger Article 50 which would begin the Brexit process.

The government had argued that it possesses the power to trigger the clause – which would formally begin the UK’s withdrawal, from the regional bloc – under the royal prerogative clause. But opponents said an issue which would change existing law needed the approval of Parliament, despite the earlier referendum vote to leave the body.

The Superme Court agreed with the petitioners, in the judgement read by President Lord Neuberger.

“By a majority of eight to three, the Supreme Court today rules that the government cannot trigger Article 50 without an act of Parliament authorising it to do so.” he said.

He added: “Withdrawal effects a fundamental change by cutting off the source of EU law, as well as changing legal rights.

“The UK’s constitutional arrangements require such changes to be clearly authorised by Parliament.”

After the judgement, Brexit Secretary David Davis promised a bill would be delivered for the House’s perusal and approval ‘within days’.