Theresa May has said she accepts that the “logical conclusion” of the high court judgment on Brexit is that the government would have to pass an act of parliament before it could trigger article 50, the formal process for leaving the European Union.

The government has said it will appeal against Thursday’s unexpected high court ruling, which stated that MPs needed to vote on triggering article 50. Downing Street has insisted it will stick to the timetable of invoking article 50 before the end of March 2017.

Asked whether the prime minister agreed with the Brexit secretary, David Davis, that if the judgment is upheld by the supreme court next month the government will have to put a bill before parliament, she said: “What David Davis was setting out is what would be a logical conclusion to draw from the judgment from today.”



Davis had said: “The judges have laid out what we can’t do and not exactly what we can do, but we are presuming it requires an act of parliament, therefore both Commons and Lords.”

A formal bill would grant MPs and peers the opportunity to stage a full debate before article 50 is triggered; to table amendments and, some hope, debate the broad principles on which the government will conduct negotiations with the other 27 EU member states.

May has requested a phone call with the European commission president, Jean-Claude Juncker, on Friday morning, in which she will reassure him that the government is continuing with its plans and sticking to the timetable set out at the European council. She is also expected to seek to reassure other key EU figures, including the council president, Donald Tusk.

Some in Westminster believe the high court decision has made the prospect of an early general election more likely by increasing the risk that the prime minister will be unable to manage the tensions within her own party.

Dominic Raab, the Tory MP and former minister, said: “If we get to the stage where effectively [some MPs] are not willing to allow this negotiation to even begin, I think there must be an increased chance that we must go to the country again. I think that would be a mistake and I don’t think those trying to break the verdict of the referendum would be rewarded.”



May’s spokeswoman insisted: “Our position has been clear that there should not be an election before 2020; that remains the prime minister’s view.”

Pro-remain MPs hope they can use the opportunity for parliamentary scrutiny created by the ruling to argue against a hard Brexit, where the UK would give up membership of the single market, as well as the customs union that allows free circulation of goods. It also gave further hope to the Scottish government of getting a greater say in the Brexit negotiations.

No 10 attempted to play down the significance of the ruling, insisting that the plan for Brexit remained on track. “The prime minister is clear and determined that this government will deliver on the decision of the British people and take us out of the EU. We are determined to continue with our plan, preparing for negotiations and sticking to the timetable we set out,” it said.

“We have no intention of letting this decision derail our timetable for triggering article 50.”

Government lawyers 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.”

May’s spokeswoman said the prime minister was working from Downing Street as usual and would not be making any public statement on Thursday about the government’s defeat in court.

May will send a cabinet minister to the House of Commons on Monday to make a statement about the ruling, but she will not attend because she will be on a trade trip to India.

Nicky Morgan, the former education secretary, said she believed colleagues on all sides of the Commons would vote in favour of triggering article 50, but said “democracy has been asserted”.

“I am also very confident in colleagues in parliament; we are very aware of how people voted – 17 million – to leave the EU. I expect parliament will approve the triggering of the article 50 process. It’s a question of law.”

The Labour leader, Jeremy Corbyn, said: “This ruling underlines the need for the government to bring its negotiating terms to parliament without delay. Labour respects the decision of the British people to leave the European Union. But there must be transparency and accountability to parliament on the terms of Brexit.”