UK Prime Minister Boris Johnson told MPs earlier that if President Vladimir Putin “doubles down, then so shall we”.

He also said the government would match donations by British people to the Disasters Emergency Committee appeal for Ukraine, starting with £20m.

Opposition leader Keir Starmer urged the prime minister to take action against Russians he says are linked to Putin.

He says Roman Abramovich - the owner of Chelsea Football Club – is “a person of interest... because of his links to the Russian state and his public association with corrupt activity and practices”.

He also raises the case of Putin’s former deputy prime minister, Igor Shuvalov, who he said owned “two flats not five minutes’ walk from this House – they are worth over £11m”.

Boris Johnson replies that “there was more to be done” but adds that the UK has taken "a leading role” in implementing sanctions against Russia.

The BBC has contacted Abramovich for a comment. He has previously denied having close financial ties with Vladimir Putin or the Kremlin.