The life of leading Kremlin critic Alexei Navalny "hangs in the balance" as he continues his hunger strike in prison, one of his closest aides said in a video Sunday as he called for mass protests across Russia.
"We don't know how long he can hold on. But it is clear we do not have time," the aide, Leonid Volkov, one of Navalny's top strategists, said in the video, which was posted on YouTube and Navalny's website.
Calling for demonstrations across Russia on Wednesday, Volkov said the quick timetable was because Navalny's condition is critical and his "life hangs in the balance."
Navalny, 44, President Vladimir Putin's most visible and persistent critic, started a hunger strike 18 days ago to protest prison authorities' refusal to allow a private doctor to see him to diagnose severe back pain and loss of feeling in his legs.
The Russian penitentiary service says he is getting adequate care.
White House national security adviser Jake Sullivan said on CNN on Sunday that there would be consequences if Navalny died in custody.
"We have communicated to the Russian government that what happens to Mr. Navalny in their custody is their responsibility and they will be held accountable by the international community," he said.
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Dr. Yaroslav Ashikhmin said Saturday that test results he received from Navalny's family showed sharply elevated levels of potassium, which could lead to cardiac arrest, and signs of kidney failure.
"Our patient could die at any moment," he said.
There was no immediate comment from police or government officials about the call for protests, but the response is likely to be harsh.
Police arrested more than 10,000 people during nationwide protests in January calling for Navalny to be freed, among other demands.
Navalny's team declared a moratorium on the demonstrations to prevent violence, saying it would hold a big protest once 500,000 people had registered online to take part.
While that number has not quite been reached, with nearly 460,000 having registered so far, Volkov said the time to act was now. "It is no longer possible to wait and postpone," he said. "An extreme situation requires extreme solutions."
State prosecutors in Moscow asked a court Friday to label Navalny's anti-corruption group, which has investigated the Kremlin elite and Putin himself, and its regional headquarters as "extremist" organizations, the state news agency Tass reported. The human rights organization Amnesty International said the request was a "new attempt to fully shut down dissent" in Russia.
The protests Wednesday have been scheduled for symbolically resonant locations — Manezh Square in Moscow, just outside the Kremlin walls, and St. Petersburg's sprawling Palace Square.
Russian officials have denied any involvement, and they even questioned whether Navalny had been poisoned, which several European laboratories confirmed.
Navalny was ordered to serve 2½ years in prison on the grounds that his long recovery in Germany violated a suspended sentence he had been given for a fraud conviction in a case that Navalny says was politically motivated.