The European Parliament on Thursday awarded the Sakharov human rights prize to Ukrainian Oleg Sentsov and called for Russia to free the filmmaker, jailed after opposing the annexation of his native Crimea.
In bestowing the honour, the European Union's elected assembly took Russian President Vladimir Putin again to task over what it sees as his illegal occupation of Ukraine.
Russia's foreign ministry slammed the award as "an absolutely politicised" move.
In announcing the prize, European Parliament President Antonio Tajani said Sentsov's case reminded the assembly it has a duty to defend human rights everywhere.
"Through his courage and determination, by putting his life in danger, the filmmaker Oleg Sentsov has become a symbol of the struggle for the release of political prisoners held in Russia and around the world," Tajani said.
"The European Parliament is expressing its solidarity with him and his cause," the Italian politician told the assembly in Strasbourg, France. "We ask that he be released immediately." Sentsov, 42, is serving a 20-year sentence in a Russian penal colony north of the Arctic Circle based on his 2015 conviction for an arson plot in Crimea.
Russia annexed the Ukrainian territory in 2014, triggering European and US sanctions.
Ukrainian President Petro Poroshenko hailed the decision to give the award to Sentsov.
"I am sure that this decision of the European Parliament will bring nearer the release of Oleg Sentsov," he said on Facebook.
Sentsov started a hunger strike on May 14 demanding the release of all Ukrainian prisoners in Russia, and his deteriorating health provoked an outcry from the international community.