Russia's lower house voted 293-45 in favor of the draft legislation, which would prevent members of "extremist" organizations from becoming lawmakers. Navalny's FBK is on the verge of being added to that list.
Alexander Murakhovsky, the first doctor to treat Alexei Navalny after he was poisoned with a nerve agent last year, reappeared after going missing Friday.
The jailed Kremlin critic's network of regional campaign offices is now on a list of organizations involved in "terrorism and extremism."
In a post on his official social media channels, Navalny thanked "good people" in Russia and around the world for their support.
The state of imprisoned Russian opposition leader Alexei Navalny's health is making headlines globally, with his supporters urging mass protests. It is a race against time before his allies are forced underground.
Jailed Russian opposition figure Alexei Navalny has announced on social media he will go on hunger strike until he receives proper medical treatment.
Two top UN officials said Russia is to blame for the near-fatal poisoning of the prominent Kremlin critic. The human rights experts said an international investigation should be carried out as "a matter of urgency."
The Kremlin critic was arrested on his return to Russia from Germany in January. He is serving time in prison, following a trial that Navalny dismissed as a tool to silence him.
Yulia Navalnaya, the wife of imprisoned Kremlin critic Alexei Navalny, reportedly flew to Germany from Moscow's Domodedovo airport. The reasons for her trip to Germany were not immediately clear.
Russian police raided homes and offices belonging to Alexei Navalny and his anti-corruption outfit. Navalny was arrested on January 17, and mass protests calling for his release led to 4,000 arrests on the weekend.
Russia's FSIN prison service has said it will be "obliged" to arrest Navalny if he returns, claiming he had breached terms of a suspended sentence.
Russian intelligence services have made the headlines recently: The FSB embarrassed itself in the Navalny poisoning case and the SVR is suspected to be behind cyberattacks in the US. Will heads roll now?