Three of Britain’s most senior experts in European and international law today declare that the measures announced in Strasbourg last night “do not come close” to meeting the tests set for Theresa May by backbench critics of her Brexit deal.

In an 11-page legal opinion, the lawyers say that what the Prime Minister claimed were “legal changes” will have no material effect on an agreement which allows the backstop to remain in place indefinitely. “It is crystal clear that the measures do not alter the fundamental legal effect of the backstop, as previously and correctly explained by the Attorney General,” they conclude.

The legal opinion was drawn up overnight by Lord (David) Anderson KBE QC, Jason Coppel QC and Sean Aughey. It will weigh heavily with any MPs today who were serious in citing legal reasons for opposing the Brexit deal in January because - unlike Geoffrey Cox, the Attorney General, whose expertise is in commercial law - all three are regarded as leading practitioners in the field of EU and international law.

They state that the measures announced last night do not come close to meeting the demands of Brexiter MP who have said they will oppose the deal unless there are “clearly worded, treaty level provisions which unambiguously override” the backstop. 

The legal opinion says: “The UK would not be allowed to end the backstop in the event that negotiations over its future relationship with the EU cannot be brought to a satisfactory conclusion  - or provide the UK with a right to terminate the backstop at a time of its choosing, or indeed at any time, without the agreement of the EU.

“The furthest they go is to reiterate the possibility that the backstop might be suspended in extreme circumstances of bad faith on the part of the EU which are highly unlikely to be demonstrated…That was only ever a very limited risk. The far greater risk of being held in the backstop indefinitely as a result of the failure of good faith negotiations remains unmitigated. “

It also casts doubt on the value of the UK’s unilateral declaration which suggests the backstop could be ended if negotiations with the EU failed. “Whether or not the UK’s understanding of the Withdrawal Agreement is correct will be a matter for the Court of Justice of the EU, which is likely to be sceptical not least because the UK’s declaration goes beyond the terms of the joint instrument,” says the legal opinion issued today.


Dominic Grieve QC MP, the former Attorney General and a leading supporter of the People’s Vote campaign, said:

“I have had the chance to look at the document produced last night and I’m quite clear in my mind it does not allow the UK to terminate the backstop in the event of as breakdown in negotiation; it does not allow the UK to terminate the backstop at a time of its own choosing. The advice issued today from Lord Anderson, Jason Coppel and Sean Aughey reinforces my view.

“In Parliament today I will continue to argue that the agreement does not bear any relationship to what we were offered in the last referendum of 2016. It is significantly different and therefore it should go back to the people - they have a right to vote on this and decide whether to go ahead.”


Notes to Editors:

  1. The legal advice commissioned by the People’s Vote campaign was drawn up by three barristers in independent practice:
  • David Anderson (Lord Anderson KBE QC) is described in the major legal directories as “the leading EU public law silk” (Chambers & Partners, 2019) and “the top barrister for EU law” (Legal 500, 2018-19).  Some 150 appearances in the European Court of Justice place him among the most respected and experienced of all practitioners in that forum. He has been listed by The Times as one of the UK’s 100 most influential lawyers, by the Halsbury Legal Awards as “Legal Personality of the Year”, and by the Evening Standard as one of London’s 1000 most influential people. Having served for six years as Independent Reviewer of Terrorism Legislation, in 2018 David was awarded KBE In the Queen’s Birthday Honours for services to national security and civil liberties.  In July 2018 he was introduced to the House of Lords as a cross-bench “People’s Peer”. Link:
  • Jason Coppel QC is a leading public law silk, with a strong record of acting both for and against the Government in constitutional and EU law cases.  He was part of the Government's legal team in the Gina Miller Article 50 litigation and in its Brexit-related litigation against the Scottish Government.  His advice to the Equality and Human Rights Commission was extensively quoted in Parliamentary debates on the EU Withdrawal Bill.  He was EU and Competition Law Silk of the Year 2018. Link:
  • Sean Aughey is described in the legal directories as “absolutely fantastic for public international law” (Legal 500, 2018-19).  He is regularly instructed as counsel in cases before the International Court of Justice and international tribunals. Link:




Notes to editors 

The legal opinion is available here.