AS INSTRUCTING solicitor on what has become known as the Article 50 court case, Balfour & Manson chairman Elaine Motion could not have been happier when the Court of Justice of the European Union delivered its highly anticipated Brexit ruling on Monday.

Although an opinion released by the court’s advocate general Manuel Campos Sanchez-Bordona last week had indicated that the European judges were likely to rule that the UK could unilaterally cancel Brexit, Ms Motion says it wasn’t until the official judgment was released that the claimants were able to breathe a sigh of relief.

“The European court has endorsed completely our position and even gone a bit further because they have confirmed that revocation [of Article 50] can take place if an extension to the time period is agreed with Europe,” she says. “That was the missing link from the advocate general’s opinion. It’s exactly what our clients had hoped for.”

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Ms Motion first began working on the case a year ago after getting together with advocate Aidan O’Neill QC and Good Law Project founder Jolyon Maugham QC to seek clarity on whether the UK could unilaterally revoke the Article 50 letter sent to trigger Brexit or whether it would need the agreement of the EU’s 27 other member states.

Having put together a cross-party claimant group made up of MPs, MEPs, MSPs and – latterly – Mr Maugham himself, the legal team initially asked the Court of Session to give them that answer, with the matter being batted back and fore between the Inner and Outer Houses before finally making its way to Luxembourg last month.

“We were blocked at the first hurdle,” Ms Motion recalls. “We had to get permission to proceed but the [UK] Government objected to that and the Lord Ordinary upheld that.

“Then we went to the Inner House of the Court of Session, which gave us permission, and it went out to another single judge. We had the hearing before Lord Boyd, who threw it out as well, and then it went back to the appeal court.

“It’s been like snakes and ladders – we’ve been going up to come back down again – but from 3 October, when the Inner House referred the matter to the European court, it’s moved at break-neck speed.”

Not that the ECJ’s judgment is the final word on the matter, with the case due to go back to the Court of Session on December 20. While the judgment from Europe should make it easier for the Scottish judges to make their ruling on whether Brexit can be cancelled, the bigger question for Ms Motion’s claimants will be how that can happen.

“What has to happen next is that the European judgment has to be endorsed by the Court of Session and a declarator announced, but whether that happens is a matter entirely for the judges,” Ms Motion says. “Then there’s the how – how Article 50 can be revoked is still to be answered. We’ve never been in this territory before.”

Not that Ms Motion has ever been afraid of entering unchartered territory. Indeed, thanks to its litigation focus Balfour & Manson, which Ms Motion has led for the past four years, has been able to make a name for itself in that respect, with Ms Motion often working alongside Mr O’Neill to break new ground.

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From prisoners’ rights and fox hunting to the Scottish Government's named person scheme and the misdiagnosis of breast cancer, Ms Motion has been involved in numerous high-profile cases that have had a wide-reaching impact. Valerie Cuthbertson versus Friends Provident is one she is most proud of.

“That was a critical illness claim where the insurers declined to pay out and it changed the law in the UK on health insurance claims and the way insurers can go about refusing to pay,” she says.

Speaking before the European judges handed down their ruling on the Article 50 case, Ms Motion said the case would be seen as a success regardless of what they decided because it would have brought clarity to an otherwise vexed area of the law. That, ultimately, is what gives her the greatest satisfaction in her role.

“The best cases are those where I see that I can actually change people’s lives or even make them feel better because they’ve asked questions,” she says.

“For Valerie Cuthbertson it changed her life and the lives of people across the UK. The Brexit case, too, has the potential to change lives.”