Jailed coordinator of Russia's Left Front movement Sergei Udaltsov is in critical condition, his wife Anastasia said on Sunday.
The opposition leader was arrested on December 4 over the fact that he has not served the full term of his previous administrative arrest and escaped from a hospital, police said.
Udaltsov's lawyer Violetta Volkova told RIA Novosti that the man has gone on a hunger strike in protest.
The man is currently in hospital. "Doctors said that he is in critical condition. He is on intensive care," Anastasia Udaltsova said.