At the end of the implementation period, the jurisdiction of the CJEU will end. The Withdrawal Agreement ensures that the UK’s membership of the EU, and the CJEU’s jurisdiction in the UK, is wound down in a sensible and orderly way. In keeping with this, and in the interests of ensuring citizens’ rights are interpreted consistently, the UK has agreed that a very narrow group of issues will be able to be referred to the CJEU for an interpretation, having due regard to whether relevant case law already exists.
For questions that relate to the settled status of EU citizens, UK courts will be able to refer questions of interpretation to the CJEU eight years from exit day, because settled status applications will be made from exit day. They will be able to refer questions that relate to other aspects of the citizens’ rights part of the agreement for eight years from the end of the implementation period, as those other aspects will only apply from the end of the implementation period.
In practical terms, this is a very limited role: our courts currently only refer two or three of this kind of case to the CJEU every year.