Ukraine's intelligence chief 'fully confirms' Vladimir Putin has cancer
His health has also come under renewed scrutiny, with a former MI6 operative Christopher Steele telling talk radio station LBC that Putin has to take regular breaks from meetings to seek medical treatment.
He said: "Our understanding is that there's increasing disarray in the Kremlin and chaos.
"There's no clear political leadership coming from Putin, who is increasingly ill, and in military terms, the structures of command and so on are not functioning as they should."
He added: "What we do know is that he's constantly accompanied around the place by a team of doctors."
Government meetings, of which many are televised, are having to be broken into sections due to Putin's health, Steele claimed.
"It's certainly having a very serious impact on the governance of Russia at the moment."
Last month, questions around Putin;s health increased when a video from February showed him “shaking uncontrollably” during a meeting with Aleksandr Lukashenko, the president of Belarus.
That followed a report by a Russian investigative journalism group that Putin had been visited by a cancer surgeon dozens of times over a four-year period.