Whether or not the UK is allowed to accede to the Lugano Convention, it has expressed its intent, upon expiry of the transition period, to re-join in its own right the 2005 Hague Convention on Choice of Court Agreements (to which it was a party pre-Brexit by virtue of its membership of the EU, and remains a party at present by virtue of the transition period). That Convention would then apply post-transition as between the UK and the r.EU (as well as, currently, Mexico, Montenegro and Singapore).
The 2005 Hague Convention
In broad terms, the 2005 Hague Convention requires that the courts of contracting states give effect to exclusive jurisdiction clauses in favour of the courts of other contracting states. Courts of contracting states must also recognise and enforce judgments handed down pursuant to such clauses (in each case, provided that the clause was concluded at a time when the 2005 Hague Convention was in force in both relevant states). The 2005 Hague Convention is therefore narrower in scope than both the Recast Brussels Regulation and the Lugano Convention, which do not limit themselves to the effects of exclusive jurisdiction clauses, but it does to some degree harmonise allocation of jurisdiction and enforcement of judgments as between contracting states.
In order to ensure that the UK is a party to the 2005 Hague Convention in its own right at the point at which the transition period ends, it will need to deposit instruments of ratification to it. This is a straightforward, unilateral process, which does not require the consent of the other contracting parties, and the UK government has already repeatedly expressed its intention to do so.
The 2019 Hague Convention
It is worth mentioning that in 2019 the text of a new international convention concerning allocation of jurisdiction and the recognition and enforcement of judgments, the 2019 Hague Convention, was finalised. The 2019 Hague Convention is much broader in scope than the 2005 Hague Convention, and is not limited to judgments arising from exclusive jurisdiction clauses. It may, in the long term, harmonise the position in these areas not just between the UK and the EU, but between contracting states more broadly. At this stage, however, widespread ratification of the 2019 Convention is still a long way off.
The Hague Conventions – a partial solution?
In summary, therefore, the 2005 Hague Convention may provide a partial replacement for the Recast Brussels Regulation, but potentially only on a forward-looking basis for exclusive English jurisdiction clauses concluded after it has come into force for the UK as a standalone state (the status of exclusive English jurisdiction clauses concluded while it was in force for the UK by virtue of its EU membership, or during the transition period, is presently somewhat unclear, at least as regards their treatment by r.EU states). Although promising, the 2019 Hague Convention at best will only be available to litigants in several years' time – and therefore does not offer a solution in the short-term.