A member of the anti-Kremlin punk band Pussy Riot has vowed to continue her work as a political artist in her first interview with the western media since being sent to prison eight months ago.

Nadezhda "Nadya" Tolokonnikova, 23, sounded defiant in the 15-minute telephone interview from her prison colony in Mordovia, a central Russian region infamous for its high number of prison camps. She has been at the distant women's penal colony since October, serving the remainder of a two-year sentence on charges of "hooliganism motivated by religious hatred".

Tolokonnikova and two other members of Pussy Riot, Maria Alyokhina and Yekaterina Samutsevich, were found guilty in August last year after they performed a song criticising Vladimir Putin and the Russian Orthodox church in Moscow's Christ the Saviour Cathedral. Samutsevich was later given a suspended sentence.

In a phonecall monitored by prison officials, who repeatedly interrupted the conversation in order to prevent Tolokonnikova from talking about politics, the Pussy Riot founder said she had no hope that Putin's government would release her early.

A court in Mordovia is due to hold a parole hearing in Tolokonnikova's case on 26 April. Although the interview was held one day after the parole hearing date was set, Tolokonnikova, who has been kept largely in an information vacuum, said she had not heard the news.

"For me, the parole hearing means nothing," she said. "In our case, the government wants us to recognise our guilt, which of course we won't do," Tolokonnikova said. "I submitted the parole documents to show that they cannot break a person."

Pussy Riot's supporters have accused Putin of orchestrating the case against them. The women carried out their 40-second cathedral performance in the runup to a contested March presidential election that brought Putin back to the Kremlin. The highly publicised trial against them signalled the start of a sweeping crackdown on the opposition.

Tolokonnikova has also continued to appeal against her guilty verdict through the Moscow court system, and is one step away from it reaching the country's pliant supreme court. Late on Sunday, a leading judge in the Moscow appeals court denied that the case against the women of Pussy Riot was political. "We don't hear political cases," Olga Yegorova said in an interview with state-run NTV television. "It is in my power to lessen their sentence – it's not excluded that that will happen."

The case against Pussy Riot, conducted at lightning speed and rife with procedural abnormalities, highlighted the politicised nature of Russia's court system. Their guilty verdict sent a warning signal to the largely young and urban opposition, while the state's representation of Pussy Riot's performance as an attack on the church pandered to the post-Soviet growth in religious sentiment in the Russian heartland.

The next political trial due to shake the nation is that of the opposition leader Alexey Navalny, whose trial is set to start in the city of Kirov, 500 miles from Moscow, on 17 April. He has been charged with embezzlement in a case he believes has been designed to silence him.

Before being cut off by a prison official, Tolokonnikova said: "I hope they don't have the impudence to jail him – because, after all, he is even more of a media figure among the people than the members of Pussy Riot, at least in Russia.

"I'm very happy he exists, as I'm happy that any political activist exists, especially someone who is willing to spend all his time and energy to change the political situation in Russia," she said.

Tolokonnikova spends her days adhering to a strict prison regimen dominated by work in the colony's factory, sewing uniforms for various Russian officials. She said she felt fine and that "it could be worse". She takes medicine daily for persistent headaches.

Asked if she had begun to think about life after prison, Tolokonnikova said: "My life isn't going to change – there will be new key components because of the experience I've gathered here. The vectors of politics and art will continue the same."

The prison routine leaves her little free time. Whatever time she gets goes towards reading books and the many letters from supporters delivered to her twice a week. Any information from the outside world comes from the newspapers and magazines that her relatives bring her during visits.

"I try to use all my time constructively – productively, creatively. I'm trying to learn how to relate to all this with interest, and I think I am achieving it," she said. "If your mood is bad, then time goes slow. If you learn to live paying attention to life and valuing it, even here, then time isn't lost.

"That's my main task: to make it so that the time they tried to take from me isn't lost. And I think I am successful."