Three senior judges ruled that Theresa May does not have the power to use the royal prerogative and trigger Article 50 without prior authority of Parliament.
The government had argued it would not give MPs a say on Brexit negotiations ahead of invoking the mechanism.
Government lawyers had attempted to argue that the prerogative powers May demanded were legitimate as they were the only way to put into effect “the will of the people” who voted Leave in the June referendum.
The High Court ruling is seen as a defeat for the defenders of a ‘hard Brexit.’
The High Court ruling read: “We hold that the Secretary of State does not have power under the Crown’s prerogative to give notice pursuant to Article 50 of the TEU for the United Kingdom to withdraw from the European Union.”
Reporting from inside the High Court, commentator Joshua Rozenberg quoted the Lord Chief Justice Thomas of Cwmgiedd as saying “rights would inevitably be lost by [EU] withdrawal.”
“A formal announcement is expected soon on whether the government will appeal to the UK Supreme Court. It’s seen as highly likely,” tweeted Rozenberg.
— Mark Broad (@markabroad) November 3, 2016
The sterling skyrocketed against the dollar after the ruling, jumping from US$1.2365 to $1.2445. The peak exchange lasted just minutes, before reverting to $1.2383.
International Trade Secretary Liam Fox has said he is “disappointed” by the High Court decision.
In response to a question from Barry Gardiner MP, Fox told the Commons: “There will be numerous opportunities for the house to examine and discuss what the government is negotiating. When we are clear about the position we will adopt then article 50 will be triggered, but given the nature of the judgement this morning we will now have to await the government’s appeal to the Supreme Court.”
Fox added: “The government is disappointed by the court’s judgement. The country voted to leave the European Union in a referendum approved by an act of Parliament. The government is determined to respect the result of the referendum. This judgement raises important and complex matters of law and it’s right that we consider it carefully before deciding how to proceed.”
Liam Fox – government is “disappointed” by the High Court decision
— Sam Coates Times (@SamCoatesTimes) November 3, 2016
Liam Fox tells Commons the Govt is “disappointed” at the High Court Article 50 ruling but “determined” to respect referendum result #Brexit
— Andrew Woodcock (@AndyWoodcock) November 3, 2016
A Government spokesman said May and her ministers are “disappointed” with the judgement.
“The country voted to leave the European Union in a referendum approved by Act of Parliament. And the Government is determined to respect the result of the referendum,” the spokesman said.
Gina Miller, who together with other claimants brought the case to the High Court, said outside the Royal Courts of Justice she is “delighted” and hopes the judgement will bring “sobriety” to the debate.
“I hope, when Government contemplate the full judgement, that they will make the wise decision of not appealing, but pressing forward and having a proper debate in our sovereign Parliament, our mother of all parliaments, that we are so admired for around the world,” she added.
Labour’s Pat McFadden, former shadow minister for Europe, told Sky News that Parliament would not block Article 50 from being triggered, but would press the government for more information on the negotiation process.
Liberal Democrat leader and Remain campaigner Tim Farron welcomed the ruling, saying: “It is critical that the government now lay out their negotiating to Parliament, before such a vote is held.
“So far May’s team have been all over the place when it comes to prioritizing what is best for Britain, and it’s time they pull their socks up and start taking this seriously.
If handled correctly it could wrestle control of Brexit process away from more extreme elements, towards more moderate, consensual approach. https://t.co/VPK5YySFyd
— Ian Dunt (@IanDunt) November 3, 2016
“Ultimately, the British people voted for a departure but not for a destination, which is why what really matters is allowing them to vote again on the final deal, giving them the chance to say no to an irresponsible hard Brexit that risks our economy and our jobs.”
The sentiment seemed to be echoed by Scottish First Minister and Scottish National Party leader Nicola Sturgeon who dubbed the result “significant indeed.”
I now fear every attempt will be made to block or delay triggering Article 50. They have no idea level of public anger they will provoke.
— Nigel Farage (@Nigel_Farage) November 3, 2016
Acting UKIP leader Nigel Farage, however, says he fears a “betrayal may be near at hand.”
He tweeted he had a “distinct feeling” the Establishment would “not accept the June 23 referendum result.”
“I now fear every attempt will be made to block or delay triggering Article 50. They have no idea level of public anger they will provoke,” he added.
Not the best analogy, Boris! Foreign Sec says UK ‘will make Titanic success of Brexit’
Prime Minister Theresa May, who was in the audience, reportedly hung her head in her hands at the remark.
The gaffe was made at the Spectator magazine’s annual Parliamentarian of the Year awards, which saw Johnson win Comeback of the Year and May win Politician of the Year.