Mr Usmanov's company USM previously had sponsorship ties with Arsenal and - until this week - Everton.

Mr Shuvalov was formerly Russian President Vladimir Putin's deputy prime minister and is currently chairman of the management board of a Russian bank.

The BBC has contacted the two men for their response.

Under the UK government's new restrictions, their assets will be frozen and they will be banned from travelling to the UK.

British citizens and businesses will not be allowed to deal with them.

Boris Johnson said: "For as long as Putin continues his barbaric attack on innocent Ukrainians we will continue to exert every power we have to inflict maximum economic pain on Putin and his war machine."

And his Foreign Secretary Liz Truss said: "We won't stop here - our aim is to cripple the Russian economy and starve Putin's war machine."

The government said the two men had "significant interests in the UK and close links to the Kremlin".

Mr Usmanov founded USM Holding company, an investment group that owns iron, steel and copper suppliers and the Megafon telecommunications company.

The company, in which Mr Usmanov holds a 49% stake, sponsored Everton's training ground and had a naming-rights option for Everton's new stadium, due to open in 2024.

However, on Wednesday, Everton suspended the company's sponsorship arrangements, saying the club was "shocked and saddened by the appalling events unfolding in Ukraine".

Mr Usmanov's business partner Farhad Moshiri - the owner and main investor at Everton - has since stepped down from his role as chairman of USM and announced that he had severed all business links with the Russian.

As part of the deal, the Megafon branding was added to two of the towers of the stadium, one of which can be seen here

The Megafon branding was quickly removed from the stadium in the run-up to Thursday's televised FA Cup match

At the club's FA cup match against Boreham Wood on Thursday evening, Everton's players walked out draped in Ukrainian flags, behind 22-year-old Ukrainian defender Vitaliy Mykolenko who has been made captain on just his fourth appearance for his new club.

Mr Usmanov's previous ties with Arsenal ended in 2018 when he sold his 30% stake. At the time he was the second largest shareholder in the north London club.

In addition to connections with Premier League clubs, the government said Mr Usmanov owned Beechwood House in Highgate, worth an estimated £48m, and the 16th century Sutton Place estate in Surrey.

Mr Shuvalov is less well-known in the UK but the Foreign Office said he owned "two luxury apartments in central London worth an estimated £11m".

The Foreign Office also said it had established an Oligarch Taskforce to co-ordinate work to sanction further oligarchs.

Earlier this week, the EU froze the assets of the Mr Usmanov, saying he was "a pro-Kremlin oligarch with particularly close ties to Russian president Vladimir Putin".

At the time, Mr Usmanov issued a statement calling the EU's decision "unfair" and adding that he would "use all legal means to protect my honour and reputation".

Mr Shuvalov, the other man to be sanctioned, has worked in the Russian government as first deputy minister and government chief of staff, as well as acting as an aide to President Putin.

Igor Shuvalov, seen here with President Putin, is one of 13 oligarchs to be sanctioned by the UK since the invasion of Ukraine

Since 2018 he has been the chairman of the management board of VEB, one of the Russian banks recently sanctioned by the government.

On Wednesday, Labour leader Sir Keir Starmer had urged the prime minister to take action against Mr Shuvalov and accused the prime minister of being slow to target other individuals connected with the Putin government.

Government sources have told the BBC it could take weeks to put together sanctions against such people.

Labour, and some senior Conservative figures have said the UK should seize oligarchs' UK assets.

Conservative MP Tom Tugendhat, the chairman of the Commons foreign affairs committee, said: "We should be looking immediately to seize those assets linked to those who are profiting from Putin's war machine, holding it in trust and returning it to the Russian people as soon as possible."

Elsewhere, the US has announced fresh sanctions on Russian oligarchs including Mr Usmanov, Mr Shuvalov and Mr Putin's press secretary Dmitry Peskov.

Authorities in France and Germany have seized yachts owned by Mr Usmanov.

Mr Usmanov's yacht, Dilbar, is worth $600m

Meanwhile, Justice Secretary Dominic Raab says the government will look at ways to stop lawsuits being used by wealthy individuals to intimidate journalists and organisations covering their wealth and financial interests.

The government is expected to set out a number of options to alter the system, including procedural changes in courts and potential legislation.

Mr Raab told the Telegraph: "We will not have people close to Putin coming here to try and bankrupt people who shine a light on his excesses."