The UK government has threatened to sue former Chelsea Football Club owner Roman Abramovich to make sure the money from the club’s sale goes to Ukraine.

The £2.5bn in proceeds have been frozen in a UK bank account since the sale, with Mr Abramovich sanctioned after Russia’s full-scale invasion of Ukraine in February 2022.

The UK government wants the money to be for Ukrainian humanitarian aid, but Mr Abramovich has said he wants it to go to “all victims of the war in Ukraine”.

In a joint statement, Chancellor Rachel Reeves and Foreign Secretary David Lammy said: “While the door for negotiations will remain open, we are fully prepared to pursue this through the courts if required.”

They said they wanted “to ensure people suffering in Ukraine can benefit from these proceeds as soon as possible”.

They added: “The government is determined to see the proceeds from the sale of Chelsea Football Club reach humanitarian causes in Ukraine, following Russia’s illegal full-scale invasion.

“We are deeply frustrated that it has not been possible to reach agreement on this with Mr Abramovich so far”.

The delay in releasing the funds centres on a disagreement between the UK government and his lawyers.

Mr Abramovich – a Russian billionaire who made his fortune in oil and gas – was granted a special licence to sell Chelsea following Russia’s invasion of Ukraine, providing he could prove he would not benefit from the sale.

He is alleged to have strong ties to Russian President Vladimir Putin, something he has denied.

He cannot access the £2.5bn sale proceeds under UK sanctions but the money still legally belongs to him.

When he announced his decision to sell the club, he said proceeds from the sale would be donated via a foundation “for the benefit of all victims of the war in Ukraine”, which would include those in Russia.

The UK government has pushed back and argued that the funds should only be spent on humanitarian efforts inside Ukraine.

A House of Lords committee said last year said it was “incomprehensible” that Mr Abramovich’s promise to use the funds to support Ukraine remained unfulfilled, and that the assets remained frozen.

“This impasse reflects badly on both Mr Abramovich and the government, which ought to have pushed for a more binding commitment,” the report said.