MOSCOW - Allies of jailed Russian opposition politician Alexey Navalny announced nationwide protests for this Wednesday — after the opposition figure's family and personal doctors released blood analysis results that suggested Navalny was at high risk of cardiac arrest or kidney failure barring immediate care.

The planned protests fall on the same day that President Vladimir Putin delivers his annual state of the nation address from just outside the Kremlin — all but ensuring a tense standoff between Navalny supporters and police in the capital, Moscow.

Navalny's chief strategist, Leonid Volkov, announced the protests in a post to YouTube — arguing there was no time to lose.

"They're murdering Alexey Navalny — in a terrifying way right before our eyes," said Volkov.

Over the weekend, Navalny's doctors said that blood tests — provided by the opposition figure's lawyers to his family — showed Navalny's potassium count had reached a "critical level."

"This means both impaired renal function and that serious heart rhythm problems can happen any minute," said the letter, which was signed by Navalny's personal physician, Anastasia Vasilyeva, and three other doctors.

"If they don't start treating Navalny, he will die within days," warned his other physician, Alexander Polupan.

As of Sunday afternoon, prison authorities had yet to respond to their appeal for emergency medical care.

Navalny, 44, is currently on the third week of a hunger strike in an effort to gain access to medical treatment. He is serving a 2 ½-year sentence in a prison 100 kilometers from Moscow.

On Friday, the opposition leader said prison authorities were threatening to force-feed him.

Previously he has detailed efforts by prison authorities to lure him out of his hunger strike — including slipping candy into his pockets and grilling chicken in the prison barracks.

For several weeks, Navalny has described acute pain in his back that caused a loss of sensation in his legs and arms. Through his lawyers, he has also complained of a severe cough and dizziness.

Navalny insists his ailments are linked to an August 2020 poisoning attack with a military-grade nerve agent that nearly took his life, and that he and Western governments blame on the Russian government.

The Kremlin has denied any involvement but also refused to investigate the incident — maintaining there is no definitive proof Navalny was ever poisoned.

The government has also deployed state media to Navalny's prison to film reports that portray conditions at the penal colony as near ideal, and Navalny as seeking special treatment by faking his symptoms.

Yet the latest blood results suggested Navalny's very survival was at stake, said his press secretary, Kira Yarmysh, on social media.

"Right now, Alexey is dying," wrote Yarmysh in a post to Facebook. "And on the weekend his lawyers have no access to him, and nobody knows what will happen Monday."

In another widely shared post, Andrey Volna, a Moscow doctor, called on well-known physicians with ties to the Kremlin to intervene immediately.

"Today, when a murder is being broadcast 'live on air' to the whole world and the whole world sees it," wrote Volna on Facebook, "It's not a question of political preferences, it's a question of a doctor's duty."

Also sounding the alarm is a group of leading western academics and cultural figures — including Harry Potter author J.K. Rowling, Hollywood director J.J. Abrams, award-winning author Salmon Rushdie, and Radiohead singer Thom Yorke — who published an appeal in leading European newspapers and publications.

"We call on you, Mr. President, to ensure that Alexey Navalny is immediately given the medical treatment and care that he urgently requires—and is entitled to under Russian law," read the appeal.

A poisoned affair

Navalny was sentenced to prison in February for violating parole obligations dating back to a 2014 fraud conviction he argues was politically motivated to disqualify him from participating in Russian political life.

The parole violation charges appeared only after Navalny had spent months recovering in a German hospital from the poison attack. The action was widely seen as an effort by the Kremlin to strongly encourage the opposition figure to remain in exile.

Instead, Navalny announced he was returning home to Moscow, where he was promptly detained at the airport by police in January.

Following his conviction, it later emerged he would be serving out his sentence at the IK-2 facility in the town of Pokrov, a high-security prison known for imposing a strict regime of psychological pressure on prisoners, say former inmates.

In recent postings to his lawyers from prison, Navalny has detailed a grim existence aimed at breaking his will.

He described suffering from sleep deprivation as "torture," saying guards wake him up every hour throughout the night to document his whereabouts.

Other inmates are banned from speaking with him or forced by prison authorities to inform on his every move.

The United States and its European allies have demanded Navalny's release and issued sanctions against top Russian government officials and state entities involved.

On Sunday, U.S. National Security Adviser Jake Sullivan said on CNN's "State of the Union" program that "there will be consequences" if Navalny dies.

On Friday, U.S. President Joe Biden called the Kremlin's treatment of Navalny "totally unfair and totally inappropriate."

The Kremlin has rebuffed Western demands and sanctions as attempts to interfere in Russia's internal affairs.

Authorities in Moscow also maintain that any questions regarding Navalny's treatment are to be directed to the prison authorities but said that his basic needs will be met.

Washington has told Russia there will be “consequences” if the Kremlin critic Alexei Navalny dies in jail.

Navalny’s doctors say he “will die within the next few days” if he does not receive urgent medical attention for acute back pain and leg numbness.

However, Russia’s ambassador to the UK has said that Navalny is attention seeking and “will not be allowed to die in prison”.

Authorities decide to transfer Navally to hospital

The Russian state penitentiary service said Monday a decision has been made to transfer imprisoned Russian opposition leader Alexei Navalny, who is in the third week of a hunger strike, to a hospital.

The announcement comes two days after Navalny’s physician said his health was deteriorating rapidly and the 44-year-old Kremlin critic could be on the verge of death.

The state prison service, FSIN, said in a statement that Navalny would be transferred to a hospital for convicts located in another penal colony in Vladimir, a city 180 kilometers (110 miles) east of Moscow. According to the statement, Navalny’s condition is deemed “satisfactory” and he has agreed to take vitamin therapy.