Vladimir Putin reportedly wants to retreat into "self-isolation" and move to an official residence equipped with a bunker in the New Year due to health problems.
The Russian president's health is "increasingly causing concern" to his doctors and relatives, it has been claimed.
Russian opposition Telegram channel General SVR, which has long claimed Putin is suffering multiple serious illnesses, said his health has become even worse due to "stress" caused by the ongoing war in Ukraine.
The channel - which claims to have secret sources in his Kremlin circle - posted today that Putin has left himself in a "blind corner" and he will go into "self-isolation" mode next year.
Putin is said to be is running low on missiles due to the fact that even Iran - a strategic ally of Russia - is not prepared to offer assistance on the scale the country needs.
The channel said: "The president's health, which, against the backdrop of constant stress, is increasingly causing concern for doctors and Putin's relatives.
"Due to cancer, Putin has serious digestive problems and has been on a strict diet for the past few months."
He also suffers "bouts of coughing, dizziness, sleep disturbances, abdominal pain, constant nausea", as well as symptoms of Parkinson's disease and schizoaffective disorder, it has been claimed.
The channel added: "Putin is on medication all the time, and preparing the president for a public display is becoming increasingly difficult.
"To this should be added the increased risks in terms of personal security [due to the failures of his war in Ukraine].
"The whole complex of problems led the president to make a decision after the New Year to switch to the ‘self-isolation’ mode and spend most of the time in one of [his official] residences equipped with a so-called ‘bunker’."
The channel claimed that "the situation at the front is such that, given the current trends, Russian troops will be forced to leave all the occupied territories of Ukraine by the summer of next year" except Crimea.
An effort would then be made to secure Crimea and areas of western Russia that could be vulnerable if Ukraine attacked, according to the channel.
It said: "The mobilised [troops] will have to delay the final part of the military defeat at the cost of their own lives, but the result is the same and no one has any doubts about it."
The channel also claims that Putin's current plan is a transition to hand power to Agriculture Minister Dmitry Patrushev, 45, the son of his longtime right-hand man and main security adviser Nikolai Patrushev, 71.
Patrushev senior was this week sent to Iran to seek new missiles and kamikaze drones from the hardline Iranian regime.
However, in the event of Putin being forced out by the war or ill health, others believed that deputy chief of staff Sergei Kiriyenko, 60, is a more likely successor.
The anonymous General SVR channel has long claimed that Putin is suffering from abdominal cancer, Parkinson’s disease and a schizoaffective disorder.
However, its insider claims are impossible to verify. It predicted in advance the shape of Putin's mobilisation strategy.
It is reportedly authored by an exiled Kremlin lieutenant-general, known by the alias Viktor Mikhailovich.
The channel has claimed that the Kremlin is seeking to ban it but has so far failed.
Today, Russia said its troops began pulling out of the strategic city of Kherson, but Ukrainian officials said they remained cautious, fearing an ambush.
A forced pullout from Kherson - the only provincial capital Moscow has captured - would mark one of Russia's worst setbacks yet, recalling its retreat from Kyiv in the early days of the war.
Recapturing Kherson could allow Ukraine to win back lost territory in the south, including Crimea, which Moscow illegally seized in 2014.
