Early in the Brexit talks, the UK and EU produced a joint report which set out their commitments about how the UK would leave the EU, which included reference to how a border would be avoided between Northern Ireland and the Republic.
The UK planned to avoid such an outcome via its overall relationship with the EU in future, remaining close enough to the EU that border checks wouldn’t be needed for goods or people. However, the EU insisted on a clause in the joint report of December 2017 which said that if these checks couldn’t be avoided in the way the UK foresaw, “the United Kingdom will maintain full alignment with those rules of the Internal Market and the Customs Union which, now or in the future, support North-South cooperation, the all island economy and the protection of the 1998 Agreement.”
This commitment is the Irish backstop. The EU fleshed this out into a proposal suggesting only Northern Ireland remain in the EU customs union and regulatory area for goods.
The UK has consistently rejected the EU’s proposal. Talks continue about how to define the backstop in the Withdrawal Agreement, and it has become the central point of contention in reaching a deal.
Find out more – read our explainer on the origins of the Irish border.View all facts