KREMLIN critic Alexei Navalny expects to hear a verdict on Tuesday in Russia's latest criminal case against him, in which prosecutors seek to have him sent to a maximum-security penal colony for 13 years on charges of fraud and contempt of court.

Navalny is already serving a two-and-a-half year sentence at a prison camp east of Moscow for parole violations related to charges that he says were trumped up to gag him as a political opponent of President Vladimir Putin.

His national opposition movement has been labelled "extremist" and shut down, but he has continued to issue messages on social media from prison through his legal team and aides, recently urging Russians to oppose the war in Ukraine.

Navalny's spokeswoman, Kira Yarmysh, said last week that prosecutors had requested a transfer to a maximum-security jail because they said he had committed crimes in the prison camp.

"Probably it will be further from Moscow and lawyers will have difficulty entering this colony and we will not have access to Alexei," she said on Monday.

"It’s not a question of his freedom, it’s a question of his life ... They are the same people that tried to kill him already ... This is what we are afraid of."

Navalny was jailed last year when he returned to Russia after receiving medical treatment in Germany following a poison attack with a Soviet-era nerve toxin during a visit to Siberia in 2020. Navalny blamed Putin for the attack, a charge the Kremlin denies.

Yarmysh said Navalny expected the Lefortovo court in Moscow to hand down the full 13-year sentence that the prosecution had requested - but that Navalny's work would continue.

"I'm completely sure that Alexei won't be in prison for (an extra) 13 years. Putin himself won't last that long," she said.

"And we now know how to communicate with Alexei and how he can supervise our activity from prison."

After the last hearing on March 15, Navalny struck a typically defiant tone, saying on Instagram: "If the prison term is the price of my human right to say things that need to be said ... then they can ask for 113 years. I will not renounce my words or deeds." 

Many of Navalny's most prominent allies have left Russia rather than face restrictions or jail at home.

Yarmysh herself is on a wanted list, and left Russia last year after a court restricted her freedom of movement for 18 months, alleging breaches of COVID-19 safety rules.