The three jailed members of Russian punk feminist band Pussy Riot are due to learn if their sentences will be shortened.
Nadezhda Tolokonnikova, Maria Alyokhina and Yekaterina Samutsevich are expected to appear at Moscow City Court for the appeal hearing which is only expected to last one day.
The three women are currently serving two-year jail sentences for the anti-Putin 'punk prayer' they performed in Moscow's main cathedral.
Today's hearing will not include a review of evidence, only a re-assessment of the verdict in a process known in Russia as 'kassatsia'.
Their legal team says the best case scenario is that their terms are cut by six months. If not they will be sent from a Moscow jail to three separate Russian penal colonies to serve the entirety of the sentences handed to them in August.
Konstantin Goloskokov, the head of pro-Kremlin youth group Nashi, claims they have "unmasked" the remaining Pussy Riot members.
Nashi earlier announced that they had set up a "prize fund" for anyone who could offer information on the identities of the activists.
Mr Goloskokov blogged that he has passed a list of names to the police, adding that some of those listed have participated in protests and given interviews to the media as members of the punk collective.
Meanwhile the jailed members have suggested that their lawyers be nominated for the Nobel Peace Prize in a handwritten letter supporting the group:
"We are calling on our friends and supporters, parliamentarians of free countries, and culture figures to support our nomination of lawyers Feigin, Polozov and Volkova for the Nobel Peace Prize," the letter says.
"Many people say that our lawyers are not lawyers, but politicians. That is true. It can't be otherwise politically."
It also states that the lawyers defended the Pussy Riot activists "openly, making every moment of the disgraceful trial public, despite the risks to their reputation and safety".