It is the first time that the UK has leveraged the assets, frozen on account of Russia’s invasion of its neighbor, to help bankroll Ukraine’s war effort.

The loan forms part of the G7 Extraordinary Revenue Acceleration (ERA) Loans to Ukraine scheme. Under the program the G7 countries have committed to provide Kyiv with $50 billion, with the lenders recouping their money from the extraordinary profits on the immobilised Russian assets.

The news of the British loan came on the same day that the European Parliament approved an EU plan to loan Ukraine Є35 billion under the ERA loans scheme.

In a press statement, Rachel Reeves, the British finance minister, said: “Our support for Ukraine and her men and women in their fight for freedom from Putin’s aggression is unwavering and will remain so for as long as it takes.

“This new money is in Britain’s national interest because the frontline of our defence – the defence of our democracy and shared values – is in the Ukrainian trenches. A safe and secure Ukraine is a safe and secure United Kingdom.”

John Healey, the British defense minister, said the money donated by Britain would be solely for Ukraine’s armed forces, and could be used to help develop drones capable of travelling further than some long-range missiles.

Russia has repeatedly threatened retaliation to any use of frozen Russian assets to finance Ukraine, which it describes as illegal.