[7] He served as the leader of the Yabloko party's youth wing since 2001 until 2008, organizing mass protests and speaking to the media about their causes.

[12] On 23 February 2016 Yashin, despite harassment by police and hecklers, presented a report criticizing Chechen leader Ramzan Kadyrov, labeling him a danger to Russian national security and called for his resignation.

The report highlighted Kadyrov's encouragement of violence against opposition activists and federal law enforcement officials, his luxurious lifestyle and corruption, and the building of a personal army.

On 11 April 2018 Yashin announced his intention to run in the election for Moscow mayor's office and beat the incumbent Sergey Sobyanin.

[18] On 12 July, Yashin was accused by the Investigative Committee of Russia of discrediting the Russian Armed Forces and his home was searched.

On 13 July, a court ordered his pretrial detention;[19][20] Yashin was tried over a YouTube video released in April 2022 in which he discussed the discovery of murdered Ukrainian civilians in the suburban town of Bucha, near Kyiv.

[22] On 9 December, a Moscow court sentenced Yashin to eight years and six months imprisonment for his statements about the circumstances of the killings in Bucha on charges of "spreading false information" about the armed forces.

[24] In his closing remarks to the court ahead of the verdict, Yashin said: "As if they will sew my mouth shut and I would be forbidden to speak forever.

'"[6] Yashin said about Russian President Vladimir Putin that "Strong leaders are calm and self-confident, and only weaklings seek to shut everyone up, burn out any dissent.

"[6] Before his sentencing, he urged Putin to "immediately stop this madness, recognise that the policy on Ukraine was wrong, pull back troops from its territory and switch to a diplomatic settlement of the conflict".

"[21] In his closing speech, he said that "it is better to spend 10 years behind bars as an honest man than silently burning with shame for the blood that your government sheds.