Russia argues that it would ignore the order, which it terms "blatant and gross interference" in its affairs.
Russia has been ordered to release Alexei Navalny by the European Court of Human Rights, triggering a new standoff between Europe and Moscow over the fate of Vladimir Putin's staunchest critic.
Russia has said that despite an obligation to comply as a member of the Council of Europe, Russia would disregard the verdict, calling the decision of the court "blatant and gross interference in the judicial affairs of a sovereign state."
The Strasbourg-based court granted Navalny a temporary release from jail in a decision published on Wednesday because it said that the government "could not provide sufficient safeguards for his life and health."
In August, Navalny was the victim of alleged FSB poisoning, which he says was ordered by Putin, and has said his life in custody is in danger. He has been sentenced to spend the next two and a half years in prison for breaching a 2014 sentence for parole and is facing more jail time as additional charges are pressed by the government.
The decision was taken on the terms of the detention of Navalny, the court acknowledged and was not a reversal of the 2014 prosecution of embezzlement against Navalny, which was widely seen as politically motivated. He is expected this week in court to appeal against the ruling.
A copy of the judgment posted online said that "with immediate effect," Navalny should be released.
The ruling was deemed "unenforceable" by Russia's Minister of Justice, Konstantin Chuychenko, saying there was "no legal basis to free this person from custody."
Last year, Russia introduced fresh constitutional amendments specifying that Moscow was entitled to disregard foreign legal rulings that threaten its sovereignty.
In the past, it has ignored crucial ECHR decisions, including a July 2014 order to pay EUR 1.9bn in compensation to the Yukos oil empire owners gathered by Mikhail Khodorkovsky, an oligarch. Khodorkovsky was jailed on tax evasion and bribery charges for nearly a decade and the business was broken up and sold to state-controlled corporations.
In 1996, Russia joined the Council of Europe. It gradually clashed with the body and threatened to quit under Putin. In the 2014 plenary assembly of the Council over its invasion of Ukraine, Moscow lost its voting rights and regained them, controversially, in 2019.