A popular Russian Kremlin backer has dropped his support for Vladimir Putin and has demanded he face trial as a war criminal. Ilya Remeslo, 42, was a long-time regime supporter before he posted a manifesto entitled "Five reasons why I stopped supporting Vladimir Putin" to his tens of thousands of Telegram followers. The Russian online space was shocked at the long-time Putin loyalist's sudden U-turn. Mr Remeslo accused Putin of being an "illegitimate" President and said his more than two decades in power demonstrated how "absolute power corrupts". TRENDING Stories Videos Your Say "Vladimir Putin should resign and be put on trial as a war criminal. His personalised, corrupt system is doomed to collapse, as we’re seeing now with the war in Ukraine and elsewhere. "The army isn’t advancing in Ukraine, and the war is going nowhere," he told The Guardian. He added that he was prepared for "any trial" against him - adding that he bore a "certain responsibility" for supporting the regime. Some suggested he had been hacked, which he debunked by publishing a video where he repeated his claims. Other supporters said it could have been a staged political move by the Kremlin to identify those who oppose Putin. Ivan Philippov, a researcher of the pro-war movement within Russia, said he was "struggling to make sense of it". He suggested Mr Remeslo might be having a mental breakdown. The former Kremlin loyalist said: "None of this is staged. I am just speaking the truth." LATEST RUSSIA NEWS: UK prepares to sue Roman Abramovich after failing to release £2.5bn from Chelsea sale to aid Ukraine Mediterranean tourist hotspot risks disaster as 'ticking time bomb' Russian tanker approaches coast Vladimir Putin accuses Britain of 'barbaric terrorist attack' after UK missiles strike Russia He denied being contacted by anyone from within the Kremlin, saying "they wouldn't come up with such a plan." Mr Remeslo, a former member of Russia's public chamber, was known to target regime critics in the dock. He testified against Russian opposition leader Alexei Navalny in court, who is said to have been killed in prison by Russians using dart frog poison. When asked why he chose to speak out now, he said he could no longer remain silent and felt that Putin was "no longer 'one of us'," adding that his interests were "completely alien". Although not contacted by the Kremlin before the posts, he said he had received several calls throughout the morning from contacts in the security services, urging him to take down the post. Leonid Volkov, who served as Mr Navalny's chief of staff, said he initially believed the outburst was staged, but later changed his mind. "He wrote and said things that simply cannot be said. People are jailed for far less," he said. Moscow has arrested critics who have spoken out against Russia, handing a lengthy prison sentence to Igor Girkin, a prominent former separatist commander and outspoken critic of Putin. Our Standards: The GB News Editorial Charter