The Russian oligarch’s investor visa application is still being considered after his previous one, which was granted before tighter regulations were introduced in April 2015, expired.
No 10 said that while it would not comment on individual cases, it was the “logical conclusion” that some wealthy individuals who had applied under the investment visa route before the changes would no longer be eligible.
The government launched a further crackdown on wealthy investors coming to the UK after the Salisbury poisoning, increasing tensions between Britain and Russia.
Downing Street confirmed it was looking at individuals who were still in the UK and holding tier 1 visas, which allow anyone who invests more than £2m in the British economy to stay for 40 months.
Responding to the reports on the delay with Abramovich’s visa, the Kremlin claimed that Russian businesses often encountered “unfair and unfriendly” actions when applying to come to the UK.
But Theresa May’s official spokesman said: “The prime minister has been absolutely clear that our argument is not with the Russian people, our dispute is with the Russian government.”
The changes introduced in 2015 mean that Abramovich will face tougher standards when reapplying for his new tier 1 visa, which he will have to do from outside the UK, probably in Russia.
Applications can be rejected if officials believe the applicant is not in control of funds, money has been obtained unlawfully, or the origin of funds means granting a visa will not be conducive to the public good.
There has been an 84% fall in the number of investor visa applications since the reforms were introduced.
There is no suggestion that Abramovich has been involved in any wrongdoing.
Abramovich, who was last seen publicly at a court hearing in Switzerland on Friday, missed Chelsea’s FA Cup final victory over Manchester United at Wembley on Saturday. The Saratov-born businessman has owned the club since 2003.