HUNGER-striking Kremlin critic Alexei Navalny could “die at any time” as tension grows with Russia over Ukraine.
He was rushed to hospital from jail three weeks into his protest and needs urgent treatment, say aides.
America, Britain and Europe vowed to make Russian President Vladimir Putin pay if the anti-corruption campaigner dies.
Meanwhile Russian and Nato warplanes sparred over the Arctic, the Black Sea and the Pacific.
A record 150,000 Russian troops have massed on Ukraine’s borders, the EU said, raising fears of a Russian invasion.
Navalny’s supporters will hold nationwide protests tomorrow to upstage Putin’s annual state of the nation address.
Foreign Secretary Dominic Raab said: “The Russian authorities are responsible for Navalny’s deteriorating health. They must grant him immediate access to independent medical care and release him from his politically motivated imprisonment.”
Navalnly, 44, was arrested in January when he returned to Moscow after surviving a botched assassination with the nerve agent Novichok.
The EU’s top diplomat Josep Borrell said his health was “critical” and insisted Russian authorities were responsible.
Borrell said the troop build-up was “the highest military deployment of the Russian army on the Ukrainian borders ever”.
Four RAF Typhoon jets are due to deploy to the Black Sea.
