MOSCOW — Associates of Aleksei A. Navalny have been compelled to disband the imprisoned Russian opposition chief’s community of 40 regional places of work, considered one of his high aides mentioned Thursday, a step that pushes the home resistance to President Vladimir V. Putin additional underground.

The transfer was inevitable, Mr. Navalny’s aide, Leonid Volkov, said in a YouTube video, amid the Kremlin’s newest efforts to stifle political dissent. Moscow prosecutors on April 16 introduced that they might search a court docket ruling to have Mr. Navalny’s motion declared an extremist group, and the court docket rapidly ordered Mr. Navalny’s teams to halt all public exercise, together with taking part in political campaigns or referendums.

“Alas, we should be sincere: it’s unimaginable to work underneath these circumstances,” Mr. Volkov mentioned, warning that persevering with to function would expose Navalny supporters to felony prosecution. “We’re formally disbanding the community of Navalny places of work.”

Mr. Volkov predicted that whereas some places of work would shut, others would rework into impartial political entities engaged in native politics. Both means, the top of Mr. Navalny’s nationwide community — from Kaliningrad on the Baltic Sea to Vladivostok on the Pacific — represented the top of an period in Russian politics.

Mr. Navalny himself appeared by video hyperlink from jail at a court docket listening to on a special matter on Thursday — his enchantment of a February conviction for defamation of a World Struggle II veteran that resulted in an $11,500 high-quality. The court docket denied the enchantment.

It was Mr. Navalny’s first public look since he began his starvation strike demanding higher medical remedy.

Mr. Navalny ended the hunger strike final week after 24 days, saying his calls for had been partially met. On the courtroom video screens, Mr. Navalny appeared gaunt, however as he talked over the decide’s makes an attempt to interrupt his closing assertion, his voice sounded practically as forceful because it was in his dramatic courtroom appearances earlier this year.

Mr. Putin, Mr. Navalny mentioned, was making an attempt to wrap himself within the glory of the Soviet Union’s victory in World Struggle II as a way to justify his effort to remain in energy.

“Your king with no garments has stolen the banner of victory and is making an attempt to trend it right into a thong for himself,” Mr. Navalny mentioned, addressing the decide, based on a recording of his speech printed by the BBC’s Russian-language service. “All of your authorities are occupiers and traitors.”

The Navalny group’s community of places of work, began forward of Mr. Navalny’s failed try to problem Mr. Putin within the 2018 presidential election, grew into essentially the most formidable nationwide political infrastructure outdoors of the prevailing set of Kremlin-sanctioned opposition events. The places of work agitated for a boycott of the 2018 election, through which Mr. Navalny was barred from operating, and labored on a coordinated effort to undermine pro-Kremlin candidates in native and regional elections that the Navalny workforce known as “good voting.”

Emulating Mr. Navalny’s splashy corruption investigations printed on YouTube, the native places of work highlighted what they described as theft and injustice carried out by native officers.

“Most will proceed their work as self-sufficient, impartial, regional civic and political actions, with robust folks on the helm,” Mr. Volkov mentioned of the places of work. “Because of this every little thing we now have performed collectively up till now won’t have been for naught.”

Mr. Navalny’s Anti-Corruption Basis continues to function, although prosecutors are additionally searching for to have it outlawed as extremist. A few of Mr. Navalny’s associates are maintaining the muse operating from outdoors Russia; on Wednesday, they printed a video disclosing what they mentioned had been the salaries of Mr. Navalny’s loudest critics on RT, the Russian state-funded tv community.

Prosecutors have for years harried Mr. Navalny and different opposition figures, however normally underneath pretexts like violating guidelines on public gatherings, legal guidelines unrelated to their political actions or extra just lately rules towards gatherings to restrict the unfold of the coronavirus.

That method offered a pretense of authorized acceptance for political dissent, which is assured underneath Russia’s 1993 post-Soviet Structure. However this month’s effort to declare Mr. Navalny’s motion “extremist” has been distinct for immediately concentrating on the political exercise of Mr. Navalny’s nongovernmental organizations.

Hearings within the extremism case are persevering with this week — behind closed doorways, as a result of the proof has been deemed categorised. After they introduced the case this month, the prosecutors argued that Mr. Navalny’s teams had been seditious organizations disguised as a political motion. In a information launch, prosecutors mentioned that “underneath the guise of liberal slogans these organizations are busy forming circumstances for destabilizing the social and sociopolitical scenario.”

Andrew E. Kramer contributed reporting.