An outspoken pro-war blogger who has fiercely criticised Russia's military strategy in Ukraine has said he wants to challenge Vladimir Putin in next March's presidential elections.
Igor Girkin, 52, led pro-Russian fighters in eastern Ukraine in 2014, following Moscow's annexation of the southern Crimea peninsula.
Girkin is in jail awaiting trial for extremism, which he denies.
He said he wanted to disrupt the "sham" poll with the winner already known.
This comment is widely seen in Russia as a reference to President Putin, who is yet to publicly declare that he will run again.
In a letter to supporters published on Telegram on Sunday, Girkin, whose nom de guerre is Strelkov, said: "I understand perfectly well that in the current situation in Russia, participating in the presidential campaign is like sitting down at a table to play with card sharps."
But he said he hoped his attempt to unite patriotic forces would disrupt the Kremlin's plans for the polls in which "the only winner is known in advance".
"This is our chance to unite in the face of external and internal threats," he said.
He told his supporters to set up a headquarters for his campaign, and to start collecting signatures for his candidacy, even though he knew he would not be allowed to stand.