Moscow made criticism of the military illegal shortly after launching its assault on Ukraine in February 2022, and has detained thousands of the conflict's opponents since.

The bill, which according to state media has the support of all major parliamentary factions, will be introduced to Russia's lower house State Duma on Monday, speaker Vyacheslav Volodin said.

"Anyone who tries to destroy Russia and betray her should receive the punishment they deserve, and compensate for the damage to the country with their property," he wrote on Telegram.

The measure, he said, aims to punish "scoundrels" who "pour mud on our country, soldiers and officers serving in the special military operation".

The charge of spreading "false information" about the army already carries a maximum jail sentence of up to 15 years, and has been used by authorities to stifle any form of dissent.

Under the law, information about the offensive in Ukraine that does not come from an official government source can be deemed "false" and its dissemination liable to prosecution.

A Russian human rights activist was jailed for three years Thursday after a court found him guilty of "discrediting" Moscow's army in a comment posted on social media.