The UK government’s plans for Brexit have been dealt a blow by a landmark High Court ruling that the Article 50 divorce process for leaving the EU requires a vote by parliament.
The ruling means the UK government cannot use its prerogative powers to trigger Article 50. Instead, the court’s declaration means that parliament must vote beforehand, raising uncertainties over the length of the EU divorce process and whether MPs will push for amendments to any Brexit bill or even block it.
Giving the court’s decision, Lord Justice Thomas said the rights given by parliament in the European Communities Act 1972 could not be taken away by the government — only by parliament.
“In our judgment, the clear and necessary implication from these provisions taken separately and cumulatively is that parliament intended EU rights to have effect in domestic law and that this effect should not be capable of being undone or overridden by action taken by the Crown in exercise of its prerogative powers,” he said.
The UK government said it would appeal against the decision in the Supreme Court.
Liam Fox, international trade secretary, said the government was “disappointed” but added that “the government is determined to respect the result of the referendum”.
Sterling jumped to $1.2448 after the ruling, with an intraday rise as high as 1.2 per cent. But the pound gave up some of its gains after the government said it would appeal against the ruling.
The legal challenge was brought by fund manager Gina Miller with others including a Spanish hairdresser and expats living in France.
The crux of the legal challenge was whether the government could use royal prerogative powers — the residue of powers once held by the monarch — to trigger Article 50 without a parliamentary vote. The government argued prerogative powers cover foreign affairs, including the making and unmaking of treaties, and no parliamentary vote was needed.
Ms Miller said: “This case was about process not politics. My dedicated team are absolutely delighted to be able to be part of this debate and to bring some sobriety as we go forward.”
She added: “The judgment, I hope when it’s read by the government and they contemplate the full judgment, it 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.”
Nigel Farage, a leading Brexit campaigner and the outgoing UK Independence party leader, said after the ruling: “I worry that a betrayal may be near at hand.”
“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.
Theresa May has said she will trigger Article 50 of the Lisbon treaty by the end of March 2017, beginning a two-year process during which Britain has to strike a deal with the EU.
If parliament does have to vote on triggering Article 50, there is a possibility that MPs could block Brexit or table amendments to the legislation decreasing the prospect of a “hard Brexit”.
There is also the prospect that such legislation could be blocked by the House of Lords.
During the court hearing, lawyers for Ms Miller argued that parliament needed to vote before the Article 50 process began because British citizens will have “important” rights wrongly “stripped away” from them.
They argued the case was only about whether the law allows the government to give notification under Article 50. The courts are not concerned with the political wisdom of whether to withdraw from the EU.
These “fundamental rights” had been bestowed on them after Britain joined the EU and the European Communities Act 1972 was passed by parliament. The government could not now “unilaterally” take away these rights, which is what would happen if Article 50 were triggered and Britain left the EU, they argued.
David Pannick, the lead barrister for the campaigners, also argued that the case was of “fundamental constitutional importance” as it would test the limits of government power.
“The basic truth is that parliament is sovereign and when rights are conferred they cannot be taken away by the executive [government],” he told the court during the three-day hearing last month.
Lord Pannick argued that after the UK leaves the EU “all of these rights. fall away. There is simply nothing left. these rights fall away as a consequence of the UK leaving the EU.”
During the case, the government argued that while parliament would not have a vote on triggering Article 50, there would be parliamentary involvement, through “the Great Repeal Bill”. MPs would also “very likely” be able to debate the final Brexit deal, said James Eadie QC, a lawyer for the government.
Under the Constitutional Reform and Governance Act 2010, the government must give parliament the opportunity to consider treaties that are subject to ratification. The House of Commons can block a treaty indefinitely by voting against it repeatedly; it cannot amend a treaty.
The campaigners had been hopeful about their prospect of success after the government’s case appeared not to go as well as expected.
Lord Thomas said he was “baffled” by the arguments advanced by the government.
But the case was finely balanced and last week the government won an important legal challenge over Article 50 in a Northern Ireland court.
The House of Lords Constitution Committee recently concluded that it would be “constitutionally inappropriate” and set a “disturbing precedent” for the government to act on the results of the EU referendum without parliamentary approval.
But other experts believed the legal challenge was always doomed to fail because courts are reluctant to intervene in the exercise of power in foreign affairs, including treaties.
Critics such as Sir Bill Cash, a prominent Leave campaigner, have said that the “proceedings of parliament are outside the jurisdiction of the court”.