MPs have voted to trigger Article 50. The Lords now debating the Article 50 bill are unlikely to block Brexit.
But campaigners believe there will still legally be an opportunity to cancel what they see as a slow motion constitutional and economic disaster.
The People’s Challenge, one of the parties that, along with Gina Miller, forced the government to consult Parliament, has consulted lawyers about the next stage of the process.
According to the legal opinion written by three senior EU law specialists, there is an escape hatch at the end of the Brexit negotiations.
Sir David Edward, a former European Court of Justice judge, Sir Francis Jacobs, the ECJ’s former Advocate General, and the EU lawyer Sir Jeremy Lever believe that the EU can’t force Britain to leave.
This means that MPs two years hence don’t have to choose between a terrible deal or no deal at all – they can also simply revoke Article 50 and go back to being full members of the EU.
Grahame Pigney, the founder of The People’s Challenge, told me: “We want to dispel the idea that there is a Hobson’s Choice [on taking the Brexit deal or leaving it].
“It is entirely reasonable and practicable to say ‘We will reserve that decision until the end of the process’.”
The legal opinion will raise hackles on Brexiteers who believe Remain campaigners aim to halt Brexit in the courts. But what does it actually argue?
What the legal opinion says
The legal opinion considers two main questions:
a) What are the constitutional requirements, as set out by Article 50, for the UK to withdraw from the EU?
b) If these constitutional requirements are not met, could the UK withdraw the Article 50 notice, or let it lapse?
The lawyers argue that MPs must do more than vote on a Brexit deal – they must set out the terms in an act of Parliament.
There is a well-established constitutional practice of Parliament legislating to require new international agreements, particularly those concerned with the European Union, to be approved by an Act of Parliament before they can take effect.
Then, considering the constitutional question, they say “there are very strong arguments” that triggering Article 50 means a country can leave the EU “subject to the fulfilment of such constitutional requirements”.
Here’s the most crucial part of the opinion:
Therefore, if Parliament were to refuse to give legal effect to the terms of a withdrawal agreement negotiated with the European Union, or were to refuse to authorise withdrawal in the absence of any agreement, the notification given by the United Kingdom of its intention to leave the European Union could be treated as having lapsed (since the constitutional requirements required to give effect to that intention had not been met), or could be unilaterally withdrawn.
What this means
Pigney says his campaign group commissioned this legal opinion to give parliamentarians guidance, rather than to mount another challenge in the courts – although he doesn’t rule out one later on in the game.
As he put it to me: “Whether there is a court case depends on the climate in the UK when we know what a deal is and whether the government is going to try to push something past that is plainly not in the interests of the people.
“Yes, a decision was made, but people can change their minds.”
Although the Prime Minister has confirmed Brexit will mean leaving the single market, and one recent Daily Mirror poll found hints of “Bregret”, most polling so far has suggested those who voted Leave are still happy with the way they voted.
But as Pigney points out, the Brexit negotiation process is likely to take two years, if not more. And by that point, the mood of the country may be very different.