Irish backstop

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What is the Northern Ireland backstop?

The backstop is an arrangement for the Irish border that will come into effect if no other solutions to maintain the current open border can be agreed once the UK leaves the EU. It is intended to protect the Good Friday Agreement/Belfast Agreement and keep an open border between Northern Ireland and Ireland after Brexit.

Both the UK and EU agree on the need for a backstop to ensure no hard border – physical checks and infrastructure – returns to Ireland.

Why might the border harden as a result of Brexit?

The UK’s decision to leave the EU Single Market and Customs Union means that it will become a ‘third country’ to the EU. This will create, for the first time, a land border between the UK and the EU – the border between Ireland and Northern Ireland, and if no special arrangements are found for the Irish border then the EU will impose the standard checks it has at its border with any third country. These would include both customs checks (documenting what the product is and providing proof of where the good originates, as well as ensuring any tariffs are collected) and regulatory checks, to verify that goods comply with the EU’s standards.

The UK may decide not to impose checks on its side of the border – but risks being challenged in the World Trade Organization (WTO) by other countries who think this is providing more favourable treatment to goods crossing the Northern Irish land border compared to those entering via other ports.

How has the border featured in the withdrawal negotiations?

The EU guidelines for the first phase of negotiations on UK withdrawal identified the "unique circumstances on the island of Ireland". The guidelines also stated that avoiding a hard border was one of three key issues that needed to achieve ‘sufficient progress’ in phase one of negotiations – along with the financial settlement and citizens’ rights – to allow talks to begin on the framework for the future relationship between the UK and the EU.

The UK initially argued that the border could only be fully solved through the future UK-EU relationship. However, the EU, particularly the Irish Government, wanted legally binding commitments to avoiding a hard border included in the Withdrawal Agreement setting out the terms of the UK’s exit from the EU.

In Autumn 2017, in the run up to the critical December European Council, the question of the Irish border became critical to the prospect of successfully achieving ‘sufficient progress’. The two sides were forced to reach an agreement and bridge the gap between their positions.

What was agreed in the December 2017 Joint Report?

In December 2017, the two parties agreed in the Joint Report that to avoid a hard border, there are three possible solutions:

  • To achieve this objective through the overall EU-UK relationship agreed after the UK leaves the EU. This is the UK’s preferred option.
  • Should this not be possible, the UK will propose specific solutions to allow for a special post-Brexit arrangement for Northern Ireland.
  • In the absence of agreed solutions being reached by the time the transition period is scheduled to end in December 2020, the UK will maintain full alignment with the rules of the Internal Market and the Customs Union which, now or in the future, should support North-South co-operation, the all-island economy and the protection of the 1998 Agreement. This arrangement would remain in place until alternative solutions, most likely relying on advances in technology, could be introduced.

Through this agreement, the UK effectively conceded that a legally watertight solution to the border question had to be included in the Withdrawal Agreement, rather than postponed to the future relationship negotiations. This form of words allowed both sides to recommend that the requisite ‘sufficient progress’ had been made for further talks to take place, on the framework for the future UK-EU relationship. The European Council, including the Taoiseach (the Irish Prime Minister) duly signed this off in December 2017.

What happened after the Joint Report?

While the two sides agreed on the wording of the Joint Report, there was a lack of agreement on what the proposed solutions meant in practice. The focus of discussions on the border shifted to the third proposal, which became known as 'the backstop'.

In February 2018, the European Commission published a draft Withdrawal Agreement which, to deliver the backstop, proposed keeping Northern Ireland within the EU customs territory and ‘common regulatory area’ covering goods and sanitary and phytosanitary regulations. This approach, a ‘Northern Ireland specific’ backstop, would require customs and regulatory checks between Great Britain and Northern Ireland if it ever came into force.

The Prime Minister said “no UK Prime Minister could ever agree to” this proposal because it would threaten the “constitutional integrity of the UK”. The UK’s preferred approach was for any backstop to apply to the whole of the UK, not just Northern Ireland, to prevent the need for checks to take place on goods moving from one part of the UK to another.

In summer 2018, the UK Government published proposals for a temporary UK-wide customs union with the EU and, as part of its suggestions for the future relationship, a ‘common rulebook’ on goods regulations. Effectively the UK argued that the backstop was unnecessary as the future relationship would ensure there was no need for a hard border. However, the EU rejected the time-limited proposal and the idea of a UK-wide backstop, as it would prejudge the outcome of detailed future relationship negotiations.

Over summer 2018 discussions continued on the backstop, with Michel Barnier, the EU's Chief Negotiator for Brexit, attempting to 'de-dramatise' the issue by making clear that the EU’s proposal would require ‘only technical controls on goods’. The EU also sought to limit the categories of goods facing checks, building on existing animal health checks that take place between the two islands, rather than creating lots of new checks. 

But there was no concrete progress in mid-2018. The EU’s priorities were reasserted at the Salzburg summit in September 2018, when European Council President Donald Tusk said “there will be no Withdrawal Agreement without a solid, operational and legally binding Irish backstop”.

The two sides reached agreement on a draft Withdrawal Agreement in November 2018, which included a Protocol on Northern Ireland setting out the backstop. The EU made a significant concession in granting a UK-wide ‘single customs territory’, avoiding the need for customs checks between Great Britain and Northern Ireland, while the requirement for regulatory alignment is limited to Northern Ireland.

Why are there concerns about the backstop?

The backstop proved one of the most contentious issues in parliamentary debates on the draft Withdrawal Agreement. The Democratic Unionist Party (DUP) oppose it because it introduces differences in regulation between Northern Ireland and the rest of the UK, which it sees as threatening Northern Ireland’s place in the Union. A majority of people in Northern Ireland support the backstop, however, as it gives them privileged access to both the UK and EU markets. To allay these concerns, in January 2019, the UK Government published proposals on how the UK, including the Northern Ireland Executive if it ever returns, can influence both the decision to use the backstop and its governance if it comes into effect, as well as a commitment that the rest of the UK will unilaterally align with the Single Market regulations being applied in Northern Ireland.

Other Brexiteers are opposed to the backstop because it would mean the UK remaining in a customs territory with the EU, removing the UK’s ability to vary its tariffs, a key component of trade deals. They argue that the backstop removes the UK’s ability to have an independent trade policy, one of the Prime Minister’s “red lines”.

There are also concerns that once the UK is in the backstop, it will not be able to leave. The backstop is intended to apply “unless and until” alternative arrangements, which both sides agree on, can replace it. There is no clarity at this stage as to what these alternative arrangements could be, and Brexiteers fear that the backstop will end up becoming the long-term UK-EU relationship.

The Prime Minister has tried to allay some of these concerns. She exchanged letters with the European Council and Commission Presidents in early 2019 setting out their joint desire to work quickly for a future relationship after the UK leaves, meaning that the backstop will not be necessary. They also agreed that if it does come into force, it will not have any effect on the provisions of the Belfast/Good Friday Agreement and that the UK (including the Northern Ireland Executive) will have a say over any new EU legislation being included in the terms of the backstop.

But Parliament rejected the Withdrawal Agreement

On 15 January, the Government suffered the largest defeat in the Commons in more than a century, when MPs voted down the draft Withdrawal Agreement. Two weeks later, the Commons approved an amendment tabled by Sir Graham Brady, which signalled MPs would agree to the Withdrawal Agreement if the Government secures changes to the backstop. The Prime Minister then said she would seek changes to the backstop to allay MPs’ concerns.

Stephen Barclay, the Secretary of State for Exiting the EU, and Geoffrey Cox, the Attorney General, made a number of trips to Brussels to negotiate on the backstop, particularly around the UK’s ability to leave the arrangement if no alternatives are found.

These negotiations culminated in a meeting between Prime Minister and President of the European Commission Jean-Claude Juncker in March 2019, when the two sides published further documents clarifying the provisions of the backstop. These turned the joint letters of January 2019 into a ‘joint legal instrument’ which reconfirmed both sides’ plan to work quickly for ‘alternative arrangements’ after the UK leaves the EU, to avoid the need for the backstop to ever come into force.

The instrument also clarified that if the backstop comes into force, but the EU does not, "in good faith", use its "best endeavours" to negotiate an agreement to replace the backstop, then the UK can make use of the dispute settlement mechanism outlined in the Withdrawal Agreement. The Attorney General then published his legal assessment of what these new documents mean for the UK’s ability to leave the backstop. His conclusion was that while the new documents provide ‘useful clarifications’, nonetheless ‘the legal risk remains unchanged’ that the UK would have a legally-enforceable way to leave the backstop.

If Parliament continues to reject the Withdrawal Agreement, then the default position is for the UK to leave the EU in March 2019 with no deal.


Timeline of negotiations on the Irish backstop

  • March 2017: The Prime Minister triggers Article 50, beginning the countdown to Brexit
  • April 2017: European Council issues its first guidelines for Brexit negotiations, which establish the ‘aim of avoiding a hard border’
  • June – December 2017: Phase one negotiations, including discussions on the Irish border
  • December 2017: Joint UK-EU Report published on phase one of negotiations, establishing idea of a backstop that will be used ‘in the absence of agreed solutions’ to avoid a hard border and that must be included in the Withdrawal Agreement
  • February 2018: EU publishes draft Withdrawal Agreement, suggesting that if no other solutions are found, Northern Ireland would remain ‘part of the customs territory’ of the EU
  • February 2018: Theresa May says ‘no UK Prime Minister could ever agree’ to the EU’s proposals
  • June 2018: UK publishes proposal for ‘temporary customs arrangement’ to apply to the whole UK in the event of no other solution being found, avoiding the need for customs checks between UK and EU
  • July 2018: UK publishes ‘Chequers’ White Paper, which proposes ‘common rulebook’ on goods to avoid regulatory checks at borders
  • September 2018: Salzburg summit – EU confirms that ‘while there are positive elements in the Chequers proposal, the suggested framework for economic cooperation will not work’ and that ‘a solid, operational and legally binding Irish backstop’ is still necessary
  • September 2018: Theresa May says the UK will ‘set out our alternative’ solution to the backstop
  • October 2018: European Council fails to deliver Withdrawal Agreement
  • November 2018: Special Council agrees draft Withdrawal Agreement
  • December 2018: The Government delays ‘meaningful vote’ on Withdrawal Agreement
  • January 2019: The Government publishes ‘reassurances’ on the backstop and exchanges letter with EU Council and Commission Presidents, setting out joint ambition to avoid backstop through future relationship
  • January 2019: Meaningful vote – Parliament rejects the Government’s deal
  • January 2019: Parliament approves the “Brady amendment”, seeking changes to the backstop
  • February 2019: Further negotiations between Stephen Barclay, Secretary of State for Exiting the EU; Geoffrey Cox, Attorney General; and the EU
  • March 2019: The Government and the EU publish “joint instrument” on the backstop; Cox publishes legal advice
Update date: 
Tuesday, March 12, 2019