Russia’s richest man, Vladimir Potanin, took the dispute with his ex-wife to the UK’s top court in a bid to avoid facing one of the world’s largest divorce claims, as he warned against the “generosity” of the English courts.
Lawyers for the sanctioned billionaire asked Supreme Court judges on Tuesday to overturn a previous ruling that cleared the way for Natalia Potanina to renew her multilbillion dollar claim in London. Potanin has a net worth of $29.3 billion, according to the Bloomberg Billionaires Index.
The case is set to test UK laws that have led to London being dubbed the world’s divorce capital as judges tend to favor an equal split of assets between spouses. Potanina’s lawyers estimated in 2019 that the size of her claim could potentially be as much as $9 billion.
The English courts “are renowned for their generosity” in their approach to divorce cases, Potanin’s lawyer Edward Faulks said in court. But the current legislation “encourages forum-shopping in big money cases such as this.”
In the UK, the largest publicly known court award in a divorce is currently £450 million to the wife of billionaire Farkhad Akhmedov — though the two settled with a payment of less than one-third of that amount.
Judges previously said that Potanina received a “paltry award” in prior Russian divorce proceedings, given the billionaire’s wealth and the length of their 31-year-marriage.
The case has swung back and forth with a lower court ruling accusing Potanina of “divorce tourism before she then won an appeal. The two lived in Russia throughout their marriage before Potanina bought a home in Westminster in 2014. Potanina is seeking 50% of the value of his stake in MMC Norilsk Nickel PJSC alongside dividends. That amount would far exceed $5 billion, given that Potanin owns around one-third of the shares in the metal producer.
Potanina said she received around $40 million following Russian divorce proceedings while Potanin said she ended up with $84 million.
“The costs and delay in this case have been eye-watering with no substantive progress,” lawyers for Potanina said. By January 2022, Potanin had spent some £8.4 million ($10.2 million), while his former wife had spent £1.4 million in costs.
Potanin has taken advantage of restrictions on foreign ownership of Russian assets since the Kremlin invaded Ukraine by branching out into finance and buying stakes in banks as foreign owners pulled out. Potanin was sanctioned by the UK after buying a stake in Rosbank PJSC. He was also placed on the US blacklist at the end of last year. Before that, Potanin had largely avoided western sanctions that hit other members of the Russian elite.
This story originally Appeared on Fortune