Moscow CNN  — 

The Moscow Prosecutor’s Office filed a lawsuit on Friday with Moscow City Court seeking to label jailed Kremlin critic Alexey Navalny’s anti-corruption foundation known as FBK and his headquarters as “extremist” organizations.

Meanwhile, Navalny’s supporters say that his medical condition is rapidly deteriorating. His press secretary said that Navalny was “dying” and his doctors said medical tests showed he’s at growing risk of renal failure and heart problems.

If approved, the move by prosecutors could have serious consequences for Navalny’s team in Russia. In Russian law, “extremist” organizations could be banned and liquidated, and activists who continue to work with them possibly face prison terms of up to 10 years.

“Under the cover of liberal slogans, these organizations are engaged in creating conditions for the destabilization of the social and socio-political situation,” the prosecutor’s office said in a statement on Friday.

The statement added the goals of the opposition organizations is to encourage “color revolutions,” a reference to popular uprisings in former Soviet republics which Russia considers to have been supported by Western governments.

“The actual goals of their activities are to create conditions for changing the foundations of the constitutional system, including using the scenario of the ‘color revolution.’ ”

Attending physicians for Navalny, an outspoken critic of Russian President Vladimir Putin, said Saturday on Twitter they wrote a letter to Russian prison services (FSIN) requesting access to see Navalny.