MOSCOW (NewsNation Now) — Russian authorities on Monday ordered the offices of imprisoned opposition leader Alexei Navalny to suspend their activities pending a court ruling on whether they should be outlawed as an extremist group.

Moscow’s state prosecutors have asked the court to label the groups “extremist”, a step that would effectively force the activist network set up by President Vladimir Putin’s most high-profile opponent to stop campaigning and push them underground.

That ruling would also give Russian authorities the legal power to outlaw the group’s activities, hand down jail terms to activists and freeze the groups’ bank accounts. It is a major challenge for Navalny’s embattled team, with its leader in prison and dozens of its members under arrest, targeted for raids by law enforcement or facing criminal charges.

The injunction from the Moscow prosecutor’s office was another step in a sweeping crackdown on Navalny, Putin’s fiercest critic, and his organizations. The prosecutor’s office petitioned a court earlier this month to label Navalny’s Foundation for Fighting Corruption and network of regional offices as extremist groups.

At a preliminary hearing on Monday, prosecutors asked the Moscow court to prohibit the groups from taking part in elections, organizing protests or publishing anything online, said Leonid Volkov, an associate of Navalny.

The injunction from the prosecutor’s office was posted on social media by Navalny’s allies, who reject the accusations and insist the actions are politically motivated.

“It’s a total travesty of justice and lawlessness once again in Putin’s Russia,” said top Navalny associate Lyubov Sobol.

“They’re just screaming here: We’re scared of your activities, we’re scared of your protests, we’re scared of your Smart Voting,” tweeted Ivan Zhdanov, Navalny’s top ally and director of the Foundation for Fighting Corruption.

The Smart Voting project is designed to support candidates who are most likely to beat those backed by United Russia, the party backed by the Kremlin, in various local elections. That plan was successful in some of last year’s regional balloting.

Navalny’s foundation opened 10 years ago and has since targeted high-ranking Russian officials with exposes on corruption, many in the form of colorful and widely watched YouTube videos. One of the latest postings, which has received 116 million views alleges that a lavish palace on the Black Sea shore was built for Putin through an elaborate corruption scheme. The Kremlin has denied there are any links to Putin.

Navalny’s regional campaign offices, which he began opening in 2017 as he announced a bid for the presidency before he was barred from standing election, said they would stop posting anything on social media and were suspending operations.

“Unfortunately, we can no longer work in the old format. It’s not safe for staff and our supporters,” said his group in St Petersburg. Similar messages were posted by several others.

The hearings are being held behind closed doors as authorities have classified some of the case details, said lawyer Ivan Pavlov, whose legal team is handling the case. The next hearing is due on Thursday.

The prosecutor has accused Navalny’s groups of plotting to destabilise the political situation and working to promote a popular revolution.

The Kremlin declined to comment on the action against Navalny on Monday.

Navalny was jailed in February for 2-1/2 years for parole violations on an earlier conviction that he called politically motivated. On Friday, he said he would start gradually ending a hunger strike after getting medical care.

Despite his jailing and the extremism case, Navalny’s allies hope to disrupt parliamentary elections in September with a “smart voting” strategy in which they will call on Russians to back politicians running against the ruling United Russia party.

“We have time, desire and strength to restructure our work…and to beat United Russia,” said Volkov.

Tens of thousands of people took to the streets across Russia on Wednesday in support of Navalny and more than 1,800 were detained.

Reporting by Reuters’ Anton Zverev, Tom Balmforth and AP’s Daria Litvinova. The Associated Press and Reuters contributed to this report.