By Alissa de Carbonnel
MOSCOW (Reuters) - Vladimir Putin's opponents plan a "million-man march" in Moscow on Sunday to revive their flagging protest movement and renew pressure on Russia's supreme leader on the eve of his return to the presidency.
But the opposition leaders' first attempt to organize a big rally for two months could fall flat because protests against Putin have lost momentum since his election victory on March 4.
Many Russians are angry that Putin is extending his already 12-year domination of Russia and fear he will stifle political and economic reform, but numbers could be thin because it is a holiday weekend when Russians love to head for the countryside.
Although weeks of demonstrations until March won only limited concessions from Putin, the opposition wants to show it is still a force to be reckoned with before he is sworn in on Monday for a six-year, third term as head of state.
"Putin was illegitimately elected ... We cannot stay silent and watch this disgrace," said Boris Nemtsov, a liberal opposition leader, referring to the allegations of electoral fraud that sparked the protests.
"People who are not indifferent will come to show Putin his inauguration is not a national holiday like he thinks, like a coronation, it is the funeral of honest politics."
Putin has dismissed the allegations that widespread fraud helped him win the presidential election and secured victory for his United Russia party in a parliamentary poll in December.
Users of social networking sites reported attempts by the authorities in towns outside Moscow to prevent opposition supporters coming to the capital.
They said some activists were detained by police for petty questioning, and that some received phone calls from police suggesting they should abstain from travelling to Moscow. The reports of intimidation could not be independently confirmed.
Outgoing President Dmitry Medvedev has pushed only limited political reforms through parliament following the protests, which at their height attracted tens of thousands of people in Moscow and St Petersburg but did not spread outside big cities.
But the demonstrations have deprived Putin of his aura of invincibility and opposition candidates have been trying to get a foothold on power in municipal elections, encouraged by setbacks suffered by United Russia in recent mayoral races.
LACK OF CLEAR GOALS
City authorities have approved a march by up to 5,000 people to a square across the Moscow river from the Kremlin.
The organizers hope many more will show up but their goals are not clear to everyone now Putin is coming back as president after four years as prime minister, a post he took because of a constitutional ban on three successive terms as president.
"The time for mass demonstrations has passed in the absence of political events that can provoke mass indignation, only local issues remain," said Alexei Mukhin, an analyst with the Moscow-based Centre for Political Information.
"I don't expect a million, that's for sure ... Not to mention that 'May-time barbecues' is a magical term that makes any attempt to hold a mass demonstration unsuccessful," he said, referring to Russians' love of getting out into the country.
Alexei Navalny has sought to rally support by drawing attention to the Kremlin's decision to award a state medal to the head of the Central Election Commission, Vladimir Churov.
Much of the criticism of the conduct of the December and March elections was aimed at Churov, whom the opposition dubbed "the magician".
Media was excluded from the award ceremony at the Kremlin on Thursday and news of Churov's medal was leaked to state news agency RIA by a source in the election commission. The award was a slap in the face for the opposition.
"What other cause or reason do you need to come out against such authorities?" Navalny wrote in a blog, calling on people to join Sunday's protest.
In response to the planned demonstration, pro-Putin supporters have announced their own rally, saying they expect 50,000 people to gather at a park in southeast Moscow.
A computer hacker group, Anonymous, has said it will stage its own protest by attacking government websites to show their opposition to Putin's return.
(Editing by Timothy Heritage)