* Church backs Putin as he prepares for presidential term
* Backlash against Church, anger at response to Pussy Riot
* Opposition alienated, gamble could backfire
By Alissa de Carbonnel
MOSCOW, April 4 (Reuters) - At the peak of street protests against Vladimir Putin, the Russian Orthodox Church pitched itself as a potential moderator.
Three months later, its shift towards the president-elect has become so clear - and so divisive - that it has issued an unusually tough statement saying it is under threat from anti-Russian forces for backing him.
Its decision to stand firmly behind Putin before he starts a six-year presidential term is a gamble which some experts say could yet backfire and undermine its authority in a society that has been polarised by the protests which began over alleged fraud in a December parliamentary election.
Criticism that Russia's longest-surviving institution is working hand-in-hand with the Kremlin to suppress dissent and lend legitimacy to Putin's dominance has been further fuelled by Church hardliners' uncompromising stance.
"When the Church stands on the side of one political force against another political force without the universal support of society, this is a reason for serious censure," Andrei Zubov, a historian who has studied Russian church-state relations, said.
"I have heard a lot of unhappiness from the clergy over this recently."
Led since 2009 by Patriarch Kirill, who has widely been seen as a modernising influence, the Church has taken a more active role in politics, using its privileged status as Russia's dominant faith to lobby for more power with the state.
Although it had long been close to the authorities, its behaviour has upset liberal groups, including some in the clergy, who see it as a violation of Russia's secular laws and a sign that the Church's hierarchy is out of touch with society.
The divisions became overt during a visceral public debate over the arrest last month of three members of the anti-Putin punk group Pussy Riot after it stormed into Moscow's main cathedral and sang a protest song.
The all-girl band said its "punk prayer" was a protest against "Kirill's shameless campaigning for Putin", his alleged wealth and what they see as the Church's unpious commercial dealings.
Kirill, who has called Putin's 12-year rule as president and prime minister a miracle of God, referred directly to Pussy Riot in Tuesday's statement.
His concerns are shared by other prominent clergy who have described the rising anti-clerical sentiment as "a war against the Church."
Russian society is deeply divided over Pussy Riot's protest, during which it appealed to the Virgin Mary to rid Russia of Putin in a video-taped lip-synch in Moscow's Christ the Saviour Cathedral. A clip of the incident has since been viewed by more than one million times on YouTube.
At protests demanding the release of the detained group members, supporters have donned the band's trademark brightly-coloured balaclavas and made posters portraying them as icons or nailed to the cross.
A number of clerics urged forgiveness for the three band members, two of whom have small children. The women face up to seven years in jail on "hooliganism" charges.
But the calls for leniency met with a strong response from the Patriarch.
"There are people who justify this blasphemy," the Patriarch said. "My heart breaks to know that among these people there are those who call themselves Orthodox Christians."
Nearly half of Russians polled backed his tough stance.
"This 46 percent is exactly as many people as the number who voted for Putin," said Lev Gudkov, the director of the Moscow-based Levada Centre which published the survey.
In post-Marxist Russia, he said, the Church had become the most trusted institution. More than 70 percent of Russians view themselves as Orthodox but far fewer are practising.
"Orthodoxy has become a synonym for Russianness," Gudkov said. "The Church acts as a surrogate moral authority. It is one of the few institutions that Russians believe in, so any action against the Church irks a significant part of the population."
Putin, who will be inaugurated as president on May 7, has long courted the Church, seeking the Patriarch's blessing and appearing regularly with him in high-profile televised events.
But it was not until recently that the Church won significant concessions from the state, such as a 2010 law allowing it to reclaim property confiscated by the atheist Communist state before the collapse of the Soviet Union in 1991.
"All Putin ever wanted was the symbolism of it, the symbol of unchanging Russian values," said Geraldine Fagan, author of "Believing in Russia", a book that is to be published on Russia's religious policy.
Under President Dmitry Medvedev, the Church has lobbied with mixed success for religious education in schools, chaplains in the army and reforms of juvenile justice laws, as well as for limits on gay rights and abortions. This has triggered a backlash.
"This growing anti-clerical trend is a result of the fact that the Church ceased to be just a mere flag holder and started to translate its values to society," said Andrei Zolotov, an expert on the Russian Orthodox Church.
"That is a new discourse. In a political sense, that has started to translate into lobbying."
In a sign of growing political ambitions, Russian Orthodox Church spokesman Vsevolod Chaplin floated the idea of creating an Orthodox political party this year.
Experts dismissed the initiative as unrealistic and premature, and some describe church-state relations in Russia as a perpetual tug of war.
Despite a perception that the Russian Orthodox Church has grown wealthy since the Soviet Union collapsed, insiders say it is dependent on the state for financing, tax breaks and the restitution of Church property.
"The problem of whether the authorities do or don't hand back the Church's historic, pre-revolutionary property depends on the secular authorities," Zubov said.
"A rather complex game is being played here between the church's moral authority and its material needs."
When the protests began in December, and developed into a challenge to Putin, his legitimacy came under threat.
The Church may have hoped initially to play a bigger role in mediation between Putin and the protesters, in exchange for not openly supporting public outrage over the allegations of fraud - seen by some as a moral problem, and part of the Church's remit.
Some of Kirill's early comments were ambiguous and hinted at a degree of sympathy for the protesters: He referred to a "lawful negative reaction".
But he later changed his tune and has appeared increasingly to side with Putin, above all backing him in the March 4 presidential poll.
That is a political gamble which could backfire if the protests, which have largely subsided, take off again and Putin's popularity sinks.
"Now there is fundamental questioning of how the Church is going to attract and keep parishioners if its top caste is seen as similar to a regime that is fast becoming discredited," Fagan said. (Editing by Timothy Heritage and Andrew Osborn)