The wife of stricken Russian opposition politician Alexei Navalny appealed to President Vladimir Putin in a letter on Friday to allow him to be transported from a hospital in Siberia to Germany to receive medical assistance.
The letter, which was published on social media, was sent to the Kremlin directly, a Navalny ally said.
Navalny's allies fear Navalny was poisoned and have organised medical care for him in Germany, but Russian doctors have said Navalny's condition is too unstable for him to be moved from hospital.