Governments and rights groups, as well as musicians such as Sting and the Red Hot Chili Peppers, have expressed concern about the trial, reflecting doubts that Putin - who is serving his third presidential term and could be in power until 2024 - will become more tolerant of dissenting voices.

Tolokonnikova admitted that she and other members could be seen as being guilty of ethical transgressions, but she said their actions did not meet the threshold of criminal acts. The women's lawyers had stronger terms for events surrounding the group's trial.

"I think this indictment is absurd. From the point of law, it is legal nihilism and it contradicts every existing fundamental law and international convention," said Nikolai Polozov, adding, "Unfortunately, we can declare only one thing: that the trial is political, it is held in the tradition of the trials in Nazi Germany and totalitarian trials of the Stalin times. This is very tragic."

Symbolically, the trial takes place in the same Moscow courthouse where jailed oil tycoon Mikhail Khodorkovsky was found guilty of stealing his own oil in a trial in 2010 that many Western politicians said looked like a crude Kremlin attempt to keep a man it saw as a political threat behind bars.

Charged with hooliganism, Pussy Riot members face up to seven years in prison if convicted - a punishment rights groups say would be grossly disproportionate no matter what the law says.

Violetta Volkova said the case was stacked against her clients.

"This is a socially and politically biased trial. Currently, all the motions we have filed since the start of the trial were refused by the court in all their entirety. Therefore, we believe that if this is to continue then we will be deprived of any possibility to represent our defendants," Volkova said.

"Without any doubt, our defendants will be found guilty and they will be jailed. How harsh the sentence will be I can't really say, that will be decided in the Kremlin at the last minute," she added.

The all-girl group has no lead singer, and, in order that anyone may join, its members don multi-coloured balaclavas, which have become its trademark. They numbered five when they formed in November but later expanded to 10 members, though there have been no performances in Russia since their bandmates' arrest.

The collective, who say they average 25 years of age, see themselves as the avant-garde of a disenchanted generation that is looking for creative ways to show its dissatisfaction with Putin's 12-year dominance of the political landscape.

The performance, a protest against the church's support for Putin, was part of a lively protest movement that at its peak saw 100,000 people turn out for rallies in Moscow, some of the largest in Russia since the demise of the USSR.

The stunt was designed to highlight the close relationship between the church and former KGB officer Putin, then prime minister, whose campaign to return to the presidency in a March 4 election was backed clearly, if informally, by Patriarch Kirill.