The sanctions have been seen as a means of getting wealthy and influential Russian businessmen to indirectly influence Putin to end the war.

But several oligarchs have opted to stay out of Russia since the invasion, and have claimed they have no influence over the Russian President.

In an interview with Bloomberg this week, Ukrainian-born oligarch Mikhail Fridman said that he, like others, had no influence over Putin.

On the day of the invasion, he said, he was in Moscow on business, but quickly returned to the UK, where he is now staying.