Russia rejects foreign concerns over Navalny's health
"The health of convicts in the Russia Federation cannot and should not be a topic concerning them," said Kremlin spokesman Dmitry Peskov, referring to Western countries that have stated that Russia was ultimately responsible for Navalny's condition.
The 44-year-old was imprisoned in February for more than two years on old embezzlement charges, weeks after he returned to Moscow from Germany where he had been recovering from nerve agent poisoning.
Peskov told reporters: "We do not monitor the health status of Russian prisoners".
Navalny's allies and medical professionals concluded last week that his condition was serious and that he could suffer cardiac arrest at any moment.
That assessment led his allies to call for demonstrations in more than three dozen cities across the country later this week.
The interior ministry on Monday, however, warned supporters of Navalny against taking to the streets and vowed to take action against participants in illegal demonstrations.
"Law enforcement agencies will not allow for any destabilisation of the situation and will take all necessary measures to maintain law and order in the regions of the country," the ministry said in a statement.
"Offenders will be detained and held liable according to the law."
Russia says Navalny to be transferred to prison hospital
The prominent opposition leader announced the protest three weeks ago in an bid to receive proper medical attention as his health deteriorated in a prison colony outside Moscow.
He was thrown behind bars in February for more than two years on old embezzlement charges, just weeks after he returned to Moscow from Germany where he had been recuperating from a near-fatal poisoning attack.
The prison service said in a statement that a group of doctors had "made a decision to transfer A. Navalny to hospital for convicts located on the territory of Penal Colony No 3."
"At present, A. Navalny's medical condition is deemed to be satisfactory; he is being examined by a general practitioner every day," the statement added.
The 44-year-old anti-corruption campaigner was sentenced earlier this year to serve out his sentence in Penal Colony No 2 outside the Russian capital and soon after began complaining of back pain and numbness in his limbs.
On March 31, Navalny announced a hunger strike to demand proper medical treatment and his allies said the prison authorities have threatened to begin force feeding him.
The prison service said in its statement that with Navalny's consent, "he was prescribed vitamin treatment."