The UK should reject EU demands to make the European Court of Justice (CJEU) the ultimate arbiter of the EU withdrawal agreement, an influential thinktank says today, outlining what it says are six alternative mechanisms.

In resolving disputes after Brexit, the Institute for Government warns, the CJEU will not be neutral in disputes arising from the withdrawal agreement and the future partnership. However, it says that if the government tries to insulate the UK from any CJEU influence it could end up with no deal in the negotiations. Any dispute resolution system that challenges the CJEU’s role as final arbiter of EU law would be difficult to negotiate and would probably be struck down by the court.

According to the report, options for dispute resolution which both the UK and the EU should be able to accept as compatible with their ‘red lines’ are:

  • Sign-up to the European Free Trade Association Court, with British judges added. This would allow the UK to leave the single market, but mean accepting some influence from the CJEU.
  • Create a UK-only version of the EFTA Court. This could be legally acceptable to the EU, but Brussels may see this option as the UK ‘marking its own homework’ as it would involve only UK judges.
  • An ‘arbitration arrangement’, as suggested by Brexit secretary David Davis. This would be workable for a trade deal but a legal and political minefield for the withdrawal deal, as the EU has strict rules about who interprets EU law.
  • A joint court to interpret the agreement for both sides. The European court is not likely to accept this option as it has already rejected a proposal for a joint EU-EFTA court.
  • Swiss-style dispute resolution by committee. This would probably be struck down as incompatible under EU law.
  • The WTO dispute resolution system.

The UK could use this system for trade disputes – but it will not work as a way of enforcing the non-trade elements of the agreements, such as citizens’ rights and the divorce bill.

Report author Raphael Hogarth said: ‘The CJEU is a jealous guardian of its monopoly on the interpretation of EU law. Since citizens’ rights, the divorce bill and any transitional arrangements will all be rooted in EU law, UK and EU negotiators are constrained in terms of what dispute resolution mechanism they can dream up for the withdrawal agreement. The CJEU will throw out anything which, in its view, threatens the EU’s legal autonomy.’