By Yuri Kulikov and Natalya Zinets
KIEV (Reuters) - Ukraine voted for a president on Sunday in an election marked by widespread disillusionment as an economic crisis grips, but one which is crucial to its relations with Russia and the European mainstream.
It is the first presidential election in the former Soviet republic of 46 million people since the "Orange Revolution" mass street protests in 2004 broke the grip on power of a sleazy post-Soviet leadership.
In an ironic twist, the frontrunner in Sunday's vote is opposition leader Viktor Yanukovich, once seen as a pro-Moscow stooge, whose rigged election in 2004 sparked those protests.
Opinion polls up to the start of the year, when their publication ceased under local law, consistently put the 59-year-old Yanukovich, a towering, barrel-chested man backed by Ukraine's wealthiest industrialists, out in front.
Behind him, the polls showed, was Prime Minister Yulia Tymoshenko, a style-conscious, sharp-tongued populist who has been accusing him of preparing election fraud.
Neither is expected to win an outright victory on Sunday and a second round of voting is expected on February 7.
The euphoria of the 2004 street protests, which catapulted President Viktor Yushchenko into office, disappeared quickly after the "Orange" camp dissipated into bickering and power struggles while the country dived deep into a recession.
Yushchenko has little chance of re-election, polls showed.
"I have always voted, so today I came and voted again. But I doubt that a new president can change anything," 56-year-old Iryna Sergeyeva said at a Kiev polling station, reflecting the disenchantment of many.
Analysts say it is crucial for Ukraine, which heavily depends on Russia for most of its energy needs, to navigate a prudent course in relations with its old Soviet master after bad blood between the two countries during the Yushchenko years.
The election victor will also have to revive a shattered economy and take control of collapsing state finances that have been propped up by a $16.4 billion (10.1 billion pound) International Monetary Fund bail-out programme.
Both Yanukovich and Tymoshenko have balanced their comments on Russia with the need to integrate the country with the rest of Europe, though Tymoshenko has gone furthest with her ambitious goal to take Ukraine into the EU in five years.
Yushchenko has angered Moscow with his anti-Soviet view of history and has said both Yanukovich and Tymoshenko are part of a pro-Kremlin tandem that represents a real threat to Ukraine.
BITTER EXCHANGES
Both Tymoshenko, 49, and Yanukovich, 59, have recognised the cynicism many Ukrainians now have towards the political elite and portrayed the election as heralding long-term change.
"I have voted for changes in the country for the better," Yanukovich said, after voting in Kiev. "Ukrainians want change and soon a new era of life will begin in Ukraine."
Tymoshenko portrays herself as the only real possible saviour for Ukraine which, she said, was teetering on a "razor-sharp edge of choice" and could tip into the abyss.
"I am sure that our national independent state is capable of giving its children, its citizens, a great life. I will serve that purpose all my life, so that the people feel they have someone they can lean on," she said, her voice coarse from campaigning, from her hometown of Dnipropetrovsk.
Voting ends at 1800 GMT (6 p.m. British time) with first exit polls due soon after.
Surprises cannot be ruled out. A Russian opinion poll has said former central bank chief Sergey Tigipko has been creeping up on Tymoshenko and may have overtaken her. The businessman has portrayed himself as a strong leader able to rescue the economy.
"I voted for democracy, for market reform, for the competitiveness of the country. I think that is the most important," a confident-looking Tigipko said from a polling station in central Kiev.
Some fear if he pushes Tymoshenko out in the first round, she may challenge the result, either through the courts or by trying to bring people out into the streets as she did in 2004.
A small army of international election monitors has arrived in Ukraine and are now in place across the snow-covered country.
Analysts say a lead of 10 percent or more will make Yanukovich, supported mainly by the densely-populated, Russian-speaking areas of Ukraine, feel confident of victory.
(Additional reporting by Lina Kush in Donetsk; writing by Richard Balmforth and Sabina Zawadzki, editing by Philippa Fletcher)
