Fund manager, Brian Myerson, was ordered to pay 43% of the then £25.8m marriage assets to ex-wife Ingrid under the original 2008 settlement.

She was awarded £9.5 million cash, but he took most of his shares in the couple's stocks in Principle Capital Holdings (PCH), where Mr Myerson worked.

Since then the share price has plummeted by 90% and the divorce, as it stands, leaves Mrs Myerson with 105% of the couple's assets. Her former husband, who still owes her £2.5 million in cash, said he would have to borrow money to pay her.

But three appeal judges ruled that "natural price fluctuation" did not justify a change in the settlement. Giving the court's ruling, Lord Justice Thorpe said: "When a businessman takes a speculative position in compromising his wife's claims, why should the court subsequently relieve him of the consequences of his speculation by rewriting the bargain at his behest?"