What the PM and the EU really meant in their letter exchange on the Irish border

The legal and political assurances promised by Theresa May on the backstop before Tuesday’s vote are detailed in an exchange of letters between the prime minister and Jean-Claude Juncker, the European commission president, and Donald Tusk, the European council president.

The EU’s letter is not legally binding, but the UK could use it as evidence in any future dispute over the triggering or termination of the backstop.

What the prime minister said:

The deal is at risk … because of concerns in the UK parliament about how we are delivering on our commitments in relation to Northern Ireland’s border with Ireland.

The Irish backstop solution for avoiding a hard border involves the whole of the UK staying in a customs union with the EU if an alternative arrangement cannot be found. Brexiters fear this will turn out to be a permanent arrangement, standing in the way of Britain pursuing an independent trade policy.

As you know, since the suspension of the debate in my parliament, I have proposed a legal commitment to have our future partnership in place by the end of 2021 at the very latest.

The prime minister has been fruitlessly seeking a deadline for the completion of trade talks to ensure that the backstop would only ever last for 12 months were it to come into force.

What Tusk and Juncker said:

As you know, we are not in a position to agree to anything that changes or is inconsistent with the withdrawal agreement.

The EU has insisted that the deal agreed with May is the final deal, and there will not be a renegotiation, or any legal interpretation that cuts across it. That includes attempts by May to secure a unilateral exit mechanism from the backstop, or a time limit.

On 13 December, the European council (article 50) decided on a number of additional assurances.

The 27 heads of state and government offered warm words on the temporary nature of the backstop at the last summit, and went further than before in promising to get out of the arrangement as quickly as possible should it be triggered. The EU fears that the importance of this pledge, which would have legal standing, has not been fully appreciated in parliament.

Should national ratifications be pending … the commission is ready to propose provisional application of relevant parts of the future relationship.

The EU is promising to bring the trade deal into force before the parliaments of the 27 member states have ratified its terms.

The commission can confirm that, just like the United Kingdom, the European Union does not wish to see the backstop enter into force. Were it to do so, it would represent a suboptimal trading arrangement for both sides.

Rather than hoping to trap the UK into the backstop, the EU fears that the lack of parity in terms of level-playing commitments could lead to the UK having an economic advantage. A temporary shared customs territory would also raise complications for Brussels when it sought to strike trade deals with the rest of the world.

Facilitative arrangements and technologies will be considered.

The political declaration on the future trade deal suggests that the permanent solution for avoiding a hard border would build on the customs union in the backstop. This clause in the letter emphasises that this need not be the case and the EU is open to the technological solutions backed by a large number of Brexiters, if they can be shown to work.

The commission is committed to providing the necessary political impetus and resources to help achieving the objective of making this period as short as possible.

The heads of state and government removed the suggestion in its December communique that the backstop would be in place for a “short” period, for fear that this could not be guaranteed due to the vagaries of the negotiations. The commission has done its best to shoehorn the phrase back in, and is offering biannual EU-UK summits to check on progress.