Members of Russian female punk group Pussy Riot who are still at large speak to Reuters journalists during an interview.

A Moscow judge could send three young female Russian punk band members to three years in prison on Friday for mocking President Vladimir Putin in a cathedral, a case that has sparked an outcry in the West.

Members of the once unheralded band Pussy Riot have been in pre-trial detention for five months awaiting the verdict, while global pop stars, rights groups and foreign governments alike have all rallied to their defence.

The US State Department has already angered Russia by expressing formal concern about the “politically motivated prosecution of the Russian opposition and pressure on those who express dissenting views.”

Madonna has done the same by telling cheering Moscow concert fans that she prayed for the group.

Putin himself had preferred to stay out of what quickly developed into a national drama pitting young protesters who defied his rule this winter against the might of both the authorities and the Russian Orthodox Church.

He conceded after being pressed by a reporter that the three young women in their 20s and 30s should not be judged “too severely” while stressing that the ultimate decision remained with the court.

Judge Marina Syrova will start reading her verdict on Friday at 3.00pm (11.00 GMT). The process may stretch all day long and possibly continue into next week because the law requires her to read out all the case material.

The prosecution has asked to sentence the women - Nadezhda Tolokonnikova and Maria Alyokhina, who both have young children, and Yekaterina Samutsevich - to three years in a corrective labour facility for hooliganism motivated by religious hatred.

Five band mates in all pulled on neon-coloured balaclavas on February 21 to yell out a song called Punk Prayer in Christ the Saviour Cathedral, rebuilt in the 1990s after being razed by the Soviets in a sign of the Church's revival.

The song argued the Russian Orthodox Church had become too close to the Kremlin and called on the Virgin Mary to “drive out Putin”.

Guards and people in the cathedral grabbed the women, who had climbed into a railed-off area close to the altar, and pulled them away after around a minute. The women all ran away but three were detained by police days later.

The two other women who took part have not been arrested and the prosecution in court referred to them as “unidentified participants”. Pyotr Verzilov, Tolokonnikova's husband, told AFP that they were leading “normal lives.”

This month's daily hearings were held in the same courtroom as the second trial of critical former oil tycoon Mikhail Khodorkovsky, who was seen by the West as a victim of political repression, before the judge took a nine-day break to consider the verdict.

The prosecution has depicted the protest as solely aimed at offending believers, with one of the victims accusing the women of “twitching like devils.”

In final statements delivered to a packed courtroom on Friday, the three argued that their protest was political performance art expressing their hatred of the Putin regime, not of religion.

The case was taken up by the Russian Orthodox Church as a major campaign, with Patriarch Kirill holding an open-air prayer service outside the cathedral and criticising the women for desecrating holy relics.

But the women's supporters have also led an extraordinarily effective campaign protesting their detention and criminal charges and persuaded top Russian actors and writers to sign a letter calling for the women's release.

Last week, Madonna pulled on a balaclava at her Moscow concert and revealed the words Pussy Riot written on her back in a spectacular coup de theatre.

The women's prolonged detention has caused public support for a harsh punishment to wane.

The independent Levada Centre pollster found last month that 26 percent of respondents thought the women should get a real sentence in a prison camp. Forty-nine percent said they should do community service or be fined.

Back in March, the same pollsters found that 46 percent of Russians backed at least two years in prison for the women. - AFP