Doctors in Omsk refused to authorize the transfer of Russian opposition politician Alexei Navalny to a German hospital, his spokeswoman said Friday.

Navalny remains in a coma in intensive care after a suspected poisoning his allies link to his political activity.

“The chief doctor said that Navalny is non-transportable. His condition is unstable. Family’s decision to transfer him is not enough”, - Navalny spokeswoman Kira Yarmysh tweeted. Omsk is about 4,200 kilometers east of Berlin, roughly a 6-hour flight.

The 44-year-old Navalny fell ill on a flight back to Moscow from Tomsk on Thursday and was taken to a hospital after the plane made an emergency landing in Omsk. His team says a plane with all the necessary equipment is ready to take Navalny to a German clinic.