Divorce is rarely a tidy, consensual affair.

But while many once-happy relationships can end in ugly scenes about who gets the kids, the car, the dog or the airmiles, the divorce of Natalia Potanina, once married to one of Russia’s richest men, Vladimir Potanin, could end in one of the biggest legal rows of all times, at least in financial terms.

For Potanina, who once lived in the lap of luxury, dividing her time between a fantasy palace reminiscent of Versailles near Moscow and one of two luxury yachts in the South of France, is now seeking half her ex-husband’s fortune, which could ring in at a cool $7 billion.

A leading London divorce lawyer, Georgina Hamblin, a director at Vardags law firm, which specialises in high-value divorce cases, told The Daily Beast in an email conversation: “Should she be successful in claiming 50% of the matrimonial pot the amount that she stands to receive will be stratospheric.

“Indeed if she secures the £5m ($7bn) to which she refers this will undoubtedly be the largest award ever made in England.”

Foreigners are allowed to seek justice—including divorce settlements—in London if they can prove evidence of strong links to the U.K.

This might be why, in an interview with The Guardian today, Mrs. Potanina makes much of the fact that she has been living in London for the past two years.

In the interview Potanina implies that she will likely pursue her case in the U.K. courts, if, as expected, the Russian supreme court throws out her appeal against a previous Russian court’s curious ruling that her husband, listed by Forbes as the 78th richest man in the world, had no meaningful assets.

Once Russia’s richest man, he is currently in fourth place nationally.

Potamina claims that she is being prevented from returning to her home or to Russia: “It’s traditional. Deprive me of money and drive me out of the house… There are many people who end up in this situation. I guess this is true worldwide but especially in Russia. Our society is male dominated. The law is male. The ideology is male.”

There is no barrier to the London courts reaching a different conclusion to the Russian courts.

“She may well be successful in a plea to the English courts to seek to combat any unfairness she claims to have suffered at the hands of the Russian court in the parties’ divorce proceedings there,” Hamblin says.

However, whether she would actually ever be able to get her ex to pay up is another matter. While assets based in the U.K. may theoretically be seized, he could avoid much of the judgment by simply not travelling to the U.K.

“Enforcing the terms of financial orders across multiple, and sometimes challenging, jurisdictions is often the final battle to be won in international cases such as this,” says Hamblin. “The road can be long, but with persistence and the right legal and forensic team behind them, those fighting their case through the English courts can rest assured that they have the very best legal system behind them and one that simply will not tolerate non-compliers.”

Potamina argues in The Guardian that she should be entitled to half the fortune as they were both penniless students when they met: “I did not marry an oligarch who already owned factories and steamships. We lived in my parents’ apartment,” she says.

In 2014, Potanin married his new partner, Katya, a junior employee at his firm, with whom he now has two small children.

He is reportedly building a third yacht.