A courtroom in Moscow has banned political institutions linked to the jailed Kremlin critic, Alexei Navalny, classifying them as "extremist".
Activists can risk prison sentences if indeed they continue their job and anyone who exactly publicly helps Mr Navalny's political network is now able to be barred from jogging for public office.
Writing on social press, Mr Navalny promised he would "not retreat".
However, he explained his supporters would will have to improve how they work.
Mr Navalny is found in prison for violating the terms of parole within an embezzlement case - costs he says are politically motivated.
Russian parliamentary elections are because of happen in September and thoughts and opinions polls show the ruling party losing support. Some of Mr Navalny's supporters have been planning to manage in the elections.
Following Wednesday's ruling, a court statement explained Mr Navalny's regional network offices and his Anti-Corruption Basis (FBK) have been banned with immediate benefit.
"It was found that these organisations not only disseminated details that incited hatred and enmity against government officials, but also committed extremist activities," prosecutors' spokesman Alexei Zhafyarov explained outside the court.
Mr Navalny's lawyers said they would charm against the ruling.
A message later published on Mr Navalny's Instagram account said: "We're not going anywhere. We'll digest this, sort factors out, change, and evolve. We'll adjust. We won't step again from our aims and tips. This is our nation and we don't have another one."