Alexei Navalny has made his first public appearance since holding a 24-day hunger strike, appearing gaunt but spirited during a courtroom appeal against a defamation conviction that he has called politically motivated. A photograph released by the court showed Navalny, appearing by video link, with a shaved head and wearing a prison jacket. “I am a creepy skeleton,” said Navalny, who appeared in the courtroom on a video feed. “I weighed this much in 7th grade.” Navalny, who was fined 850,000 roubles (£8,200) in February for defaming a second world war veteran who backed a “reset” of Vladimir Putin’s presidential terms, has said the case against him was concocted to further damage his reputation among Russians. In a courtroom speech, Navalny accused the government of turning “Russians into slaves” and called Vladimir Putin a “naked king”, a reference to Hans Christian Andersen’s folk story The Emperor’s New Clothes. “I want to say, my dear judge, that your king is naked, and it’s not just one boy yelling about it, millions of people are yelling about it,” he said. “Twenty years of his fruitless rule have led to this result: a crown falling from his ears, lies on television, we’ve wasted trillions of roubles, and our country continues to slide into poverty.” Unsurprisingly, he lost the appeal. The hearing comes as Navalny’s nationwide network of regional headquarters is being shut down and his Anti-Corruption Foundation, which investigates government corruption, is likely to be named an extremist organisation, threatening severe jail terms for those who continue to support him. On Thursday, Navalny and two aides, Leonid Volkov and Ivan Zhdanov, were named suspects in a criminal case into opening a non-governmental organisation alleged to endanger citizens and their rights, a charge that carries a fine or up to four years in prison. Zhdanov called the charges, which are rarely pressed, “exotic”. The new charges indicate that Navalny and his followers will probably continue to be targeted with jail time as their political organisation is dismantled. On Thursday, Volkov announced that they would be disbanding the network of more than 35 regional headquarters, calling it “impossible” to maintain. He previously told the Guardian that he expected the extremism designation, which has also been applied to groups like al-Qaida, would lead to “mass arrests”. Navalny’s wife, Yulia, also attended the hearing. He told her that he was permitted to eat 450 calories on Thursday as he slowly returns to a normal diet after the hunger strike, which he declared in protest against his medical care in a prison in the Vladimir region. Navalny is serving a two-and-a-half-year sentence on an embezzlement sentence from 2013. He was arrested in January shortly after returning from Germany, where he received treatment for novichok poisoning that he and the investigative collective Bellingcat have traced back to the FSB.