By Dmitry Solovyov MOSCOW, March 11 (Reuters) - Russia holds regional polls on Sunday viewed as a dress rehearsal for this year's parliamentary vote and a 2008 presidential election, with a liberal party sidelined and the Kremlin expected to tighten its grip on power. The United Russia party, patronised by President Vladimir Putin, looks set to win by a landslide as the economy benefits from high world prices for its oil, gas and metal exports and the Kremlin preaches stability and economic growth. The continued domination of United Russia is crucial for the election of a new loyal parliament in December and the smooth nationwide endorsement of Putin's successor in polls next March. More than 30 million Russians, or roughly a third of the electorate, are eligible to vote for legislatures in 14 regions that include major population centres like St. Petersburg and the Moscow Region. The liberal Yabloko party, harshly critical of Putin and with little support across the country, has been shut out of the election in St. Petersburg, its main stronghold where it could have won some 20 percent of votes. In contrast to the calm and well-orchestrated campaigning in most of the country, the nation's second city has seen street protests and clashes with police. Yabloko leader Grigory Yavlinsky called on his supporters to arrange exit polls of their own and to spoil ballot papers by writing in the party's name in regions where it has been shut out of the election. Most regional governors are United Russia members, and the functions of local legislative bodies have been mainly reduced to rubberstamping nominees for regional heads proposed by Putin. The Communist Party, with an ageing voter base, is seen finishing a distant second and the ultra-nationalist Liberal Democrats, mildly critical of the Kremlin, are expected to come in third. A new force, the Fair Russia party, is also running, saying its goal is to undermine the monopoly of United Russia on state power. But Fair Russia is pro-Putin and many analysts and political opponents consider the apparent bickering between the two parties a stage-managed sham. An activist for Fair Russia was stabbed outside his house in St. Petersburg early on Saturday, prompting outrage from the party's leader and Putin loyalist Sergei Mironov. "I think this is a politically-motivated crime, this is sheer lawlessness," Mironov told Ekho Moskvy radio. "Now, does this mean one can attack a party backing the president of Russia?"
