In the latest judgment in the 12-year litigation involving the divorce of Russian billionaire Vladimir Potanin and his ex-wife Natalia Potanina, the court has refused to continue allowing injunctions preventing Potanin from relying on an anti-suit injunction obtained in Russia.
The case is one of the longest-running family cases in history, with the latest decision centred around whether an anti-anti-suit injunction, anti-enforcement injunction and anti-reliance injunction granted by Justice Lieven on an emergency basis should be continued.
In arriving at the latest decision this week, Mr Justice MacDonald said the regard and deference English law makes to foreign jurisdictions outweighs the wife’s criticisms of the Russian proceedings, and found that the husband’s litigation conduct in Russia was not sufficiently unconscionable, vexatious or oppressive.
“In considering the wife’s application, I remind myself that English law attaches a high importance to international comity”, Justice MadDonald said in the written judgment. “Although the injunctive relief sought by the wife is not addressed to, nor intended to bind, the Russian court, should the court grant such relief, that relief will constitute an indirect interference in the Russian court.”
Alex Brereton, partner at Hunters Law LLP, said the case “is unlikely to dispel the perception that the law is unnecessarily complex” and the Potanins will “continue to find novel ways to extend their dispute in the English Family Court”.
The couple married in Russia in 1983 and divorced in 2014. Mrs Potanina moved to London in 2016. A Russian divorce settlement granted her less than 1% of the couple’s estimated wealth at the time. In January 2019, Mrs Potanina was granted leave by Mr Justice Cohen to apply under Part III of the Matrimonial and Family Proceedings Act 1984.
Following an application by Mr Potanin in November 2019, leave was set aside and a renewed application dismissed by Justice Cohen. In January 2021 the Court of Appeal allowed Mrs Potanina’s appeal in part and reinstated the original grant of leave, but this was overturned by the Supreme Court in January 2024.
In September 2025, the Court of Appeal allowed Mrs Potanina’s appeal, reinstated her leave, and directed the case to proceed in the Family Division. In April a court ruled in favour of Potanina’s claim for nearly £5 billion, dismissing the efforts of Potanin to bar his ex-wife from making a claim in London pending the outcome of proceedings in Russia. Over 12 years the couple have spent millions on litigation.
Justice MacDonald has provided time for an appeal.
Explaining the decision, Brereton added: “Whereas the wife has more recently been on the front foot in being granted permission by the Court of Appeal last September to bring a financial claim under Part III MPFA 1984, here the High Court has found for the husband in denying the wife’s applications (which were successful at an initial without notice hearing) to restrain him from pursuing injunctive orders granted by the Russian Court that seek to prevent her from taking steps to continue her litigation in the English Family Court.
“What does this mean for the parties? Well, in true Potanin form the court has permitted a stay of execution of its order to allow the wife to appeal to the Court of Appeal. It would be a brave practitioner to say with any certainty what the outcome of that appeal might be. If unsuccessful, however, then on the face of it the Wife faces significant financial penalties in Russia that have the potential to outweigh the full value of her claim here (c. USD $5 billion).”
