Acceding to the Hague Choice of Court Convention is one of the unilateral steps the United Kingdom is planning to take to partially close the gap that will open in the field of judicial cooperation when the Brussels Regulation falls away upon Brexit.
Immediately after Brexit had taken place (for my assessment of what is going to change see here in English and here in German, the European Commission set up a new site: The European Union and the United Kingdom – forging a new partnership. Today, it published draft negotiating directives, as a basis for its negotiation mandate.
Today is Brexit Day. The United Kingdom is leaving the European Union. It might be worth looking at what changes as of midnight today. Spoiler alert: Practically speaking, not much. Article 126 of the Agreement on the Withdrawal of the United Kingdom of Great Britain and Northern Ireland from the European Union and the European Atomic Energy Community (Withdrawal Agreement; WA) is short and straightforward: “There shall be a transition or implementation period, which shall start on the date of entry into force of this Agreement and end on 31 December 2020.”