(Bloomberg) -- A Russian court ordered opposition leader Alexey Navalny, detained Sunday on arrival from Germany where he’d been recovering from a poisoning attack, jailed for 30 days, defying U.S. and European calls to free him.The activist faces as much as 3.5 years in prison at a hearing set for Feb. 2 on charges he breached the terms of a suspended sentence. In a makeshift courtroom in a police station outside Moscow Monday, a judge ordered Navalny, 44, held until Feb. 15 for those alleged violations.The outspoken critic of President Vladimir Putin was stopped by police at passport control as he landed in Moscow from Berlin, where he’d gone for treatment after the August nerve-agent attack he and western governments blame on the Kremlin. His detention threatens a new round of tensions with the West, as well as demonstrations in Russia.Navalny will be held in Moscow’s notorious Matrosskaya Tishina prison, which is harsher than the holding cells where he was usually kept in the past, his spokeswoman Kira Yarmysh said on Twitter. The facility is where Hermitage Capital Management tax adviser Sergei Magnitsky died in 2009 from an apparent beating, according to a Kremlin human rights council.In a video appeal recorded in the courtroom Monday, Navalny called on supporters to protest. “Don’t be scared. Come out on the streets -- not for me but for yourselves and your future,” he said. Allies said they would seek to organize protests nationally on Jan. 23. They typically defy authorities’ refusal to grant permits.Before the ruling, European Commission President Ursula von der Leyen urged Russia to “immediately” release Navalny and ensure his safety, adding her voice to similar calls from the U.S., Germany, the U.K. and other governments.“Detention of political opponents is against Russia’s international commitments,” she said in a statement on Monday, also calling for a “thorough and independent” investigation of his August nerve-agent poisoning.The ruble slipped against the dollar Monday, falling to the lowest level in a week.Foreign Minister Sergei Lavrov brushed off the Western concern over Navalny, whose corruption exposes and success in galvanizing anti-government votes have increasingly needled the authorities.Dismissing the criticism as “artificial and unjustified,” Lavrov said the U.S. and its allies were just trying to distract from their domestic problems. “This is purely a question of applying Russian laws,” “Everything that is happening with Navalny in connection with his return and arrest is a matter for law-enforcement bodies,” he told reporters in an online press conference.Stopped by Russian law enforcement shortly after landing in Moscow, Navalny kissed his wife, Yuliya, before walking off with police. He spent the night in a cell in the police station in Khimki, a Moscow suburb near the airport.At the hearing Monday, Navalny sat beneath a picture of a Stalin-era secret-police chief Genrikh Yagoda. Authorities said the unusual session was held at the police station because Navalny hadn’t had a recent negative Covid-19 test, Tass reported. Prosecutors argued he’d violated the terms of the 2015 suspended sentence by failing to make required check-ins with authorities, including while he was recovering in Germany.Read More: Putin, Poison and the Importance of Alexey Navalny: QuickTakeThe move to imprison Putin’s most prominent opponent days before Biden takes office could trigger an immediate clash with the new Democratic administration.Jake Sullivan, incoming President Joe Biden’s national security adviser, blasted the Kremlin and called for Navalny’s release.For the moment, however, investors don’t see much chance of major additional sanctions.“It doesn’t sound like this is the hill the new U.S. administration intends to die on,” said Paul McNamara, who oversees $5 billion in emerging-market debt as a money manager at GAM Investments in London and holds Russian government bonds. “The noises have been subdued.”Navalny returned home amid rising political and economic tension ahead of Russian parliamentary elections this autumn. Putin, 68, whose two-decade rule makes him the longest-serving leader since Soviet dictator Josef Stalin, last year overturned term limits, allowing him to stay in power until 2036. Speculation that he may step down far sooner is building.The opposition politician, who also potentially faces separate charges of embezzlement punishable by up to 10 years in prison, decided to confront imprisonment on the calculation he’ll become a powerful symbol of resistance to Putin, according to analysts.While for years Navalny was repeatedly jailed for weeks at a time and faced assaults on the street -- at one point nearly losing his eye -- the poisoning attack marked the most serious attempt to kill him. Russia denied any involvement and said it found no proof the opposition politician was poisoned, accusing him of fabricating it as part of working for the U.S. Central Intelligence Agency.(Updates with prison where he will be held in the fourth paragraph)For more articles like this, please visit us at bloomberg.comSubscribe now to stay ahead with the most trusted business news source.©2021 Bloomberg L.P.