The UK government has signalled that the direct jurisdiction of the European Court of Justice (ECJ) over the UK will end after Brexit. But the implications for future enforcement and dispute settlement procedures will depend on the scope and depth of any UK-EU agreement.
The role the ECJ might play in any future UK-EU agreement is understandably what most commentators are focused on.
The new UK paper does not set out detailed demands but instead explores a series of precedents which it believes should inform future discussions.
The UK's central argument is that there is no precedent, and indeed no imperative driven by EU, UK or international law, which demands that enforcement or dispute resolution of future UK-EU agreements falls under the direct jurisdiction of the CJEU.
The paper distinguishes between 'enforcement' of any agreement - the day-to-day responsibility of upholding the rights that derive from the any UK-EU deal - which it argues should be a matter solely for UK and EU institutions within their given jurisdictions and 'dispute resolution' - a method of resolving disagreements between the UK and the EU about how the deal is being applied - where it sets out a number of different options.
Many have highlighted the inclusion of the word 'direct' to argue that this marks a UK climb-down or U-turn over ending the jurisdiction of the ECJ.
True, this paper presents a more nuanced analysis of the alternative options than Theresa May's insistence that Brexit will mean "an end to the jurisdiction of the ECJ", but the paper is clear that EU law will no longer have direct effect in the UK and the "question of domestic implementation of UK-EU agreements will be addressed throughout the UK's domestic legal order."
The EU's broad position on the role of the ECJ was set out in paragraph 17 of its negotiating guidelines.
The withdrawal agreement should include appropriate dispute settlement and enforcement mechanisms regarding the application and interpretation of the withdrawal agreement, as well as duly circumscribed institutional arrangements allowing for the adoption of measures necessary to deal with situations not foreseen in the withdrawal agreement.
This should be done bearing in mind the Union's interest to effectively protect its autonomy and its legal order, including the role of ECJ.
So far, so good - in theory. However, in practice, the EU has so far insisted that, on the particular issue of EU citizens' rights in the UK post-Brexit, the ECJ must be the ultimate arbiter.
The UK is understandably refusing this demand and there are signs that European politicians - such as German foreign minister Sigmar Gabriel - have acknowledged this as a case of EU over-reach.
As others have noted, the UK was never going to operate in a legal vacuum post-Brexit. UK courts will continue to keep tabs on developments in international law and other jurisdictions and the UK has an interest in aligning itself with important international developments in various fields of law.
The broad point is that the closer the UK-EU relationship, the deeper, more complex and more restrictive the day-to-day functioning of the arrangements are likely to be.
The EU has previously stated that it wants any deal with the UK to ensure a level playing field, on issues such as tax, social, environmental and regulatory measures and practices. Would the UK accept such a potentially restrictive package deal and, if so, how would this level playing field be enforced and adjudicated on?
This paper is welcome because it illustrates that the UK government is engaging seriously and thoughtfully with these issues but it can only tell us so much. Until we know the scope and depth of the proposed UK-EU agreements, it is impossible to know what the implications are for enforcement and dispute settlement.
For disputes over technical issues - for example trade and standards - technocratic working committees might be most appropriate. More sensitive issues - such as policing cooperation - might require a more political and diplomatic resolution.
What provisions will there be when an agreement cannot be reached through a formal mechanism? Would this mean suspension of part or all of the UK-EU agreement (as set out in one set of the Swiss-EU arrangements) or merely the right to introduce retaliatory measures (as provided for under the European Economic Area agreement)?
The role of judges and arbitration mechanisms are no doubt an important day-to-day detail of any future UK-EU relationship.
However, the context in which they operate will be dictated by the high politics of UK-EU relations, both in determining the long-term UK-EU deal and whether that deal holds when there is a genuine political dispute.