The Moscow City Court has rejected an appeal filed by lawyers for jailed opposition politician Ilya Yashin against an 8 1/2-year prison sentence handed to him in December on a charge of spreading false information about the Russian military amid the invasion of Ukraine.

Yashin took part in the April 19 hearing by video link from a detention center in Moscow after the court rejected his request to be physically present for the session.

"I fully understand that the only way for me to get my sentence mitigated is to repent, beg for mercy, call black as white, and also to testify against one of my friends. That will never happen," a defiant Yashin said in a statement to the court, adding that his conscience was "clean," and that he calmly accepted his fate.

Yashin, 39, is an outspoken Kremlin critic and one of the few prominent opposition politicians who stayed in Russia after a wave of repression against supporters of jailed opposition politician Aleksei Navalny and those who have spoken against Russia's full-scale invasion of Ukraine since it was launched in February 2022.

The sentence was the harshest handed down in cases of those charged with discrediting Russia's armed forces since a new law was introduced days after the invasion commenced.

The criminal case against Yashin was launched in July. The charge against him stems from his YouTube posts about alleged war crimes committed by the Russian military in the Ukrainian city of Bucha.

The outspoken Kremlin opponent has been arrested many times in the past for his protest activities.

Yashin said earlier that the authorities were trying to force him to leave Russia, which he refused to do.

As the Russian military was forced to hastily leave Bucha and Irpin, another town on the outskirts of Kyiv, after a failed attempt to capture the Ukrainian capital in March 2022, images of the dead bodies scattered around the streets of Bucha circulated around the world, sparking a wave of shock and condemnation.

Russia has denied committing the massacres, and claimed that the deaths were "staged" by Ukraine.

Ukrainian officials estimate that about 400 bodies of civilians were found in Bucha and a total of more than 1,000 throughout the region around Kyiv.

With reporting by Mediazona