Parliamentary polls have opened in Ukraine, with world heavyweight champion boxer Vitali Klitschko emerging as an unlikely challenger to the ruling party in place of the jailed opposition leader Yulia Tymoshenko.
Polling stations will close at 8pm (18:00GMT) on Sunday with exit polls expected swiftly afterwards.
The strategic former Soviet nation, nestled between the European Union and Russia, is holding the first election since Tymoshenko lost to President Viktor Yanukovych in a bitterly fought contest in 2010.
The 2004 Orange Revolution leader was jailed less than two years later on abuse of power charges brought by Yanukovych's Regions Party that both Tymoshenko and many Western nations saw as vendetta on the part of the president.
Sunday's election to the 450-seat Verkhovna Rada is seen both as a warm-up for the 2015 presidential ballot and a chance for voters to pass judgement on a jailing that has isolated Ukraine from EU states.
First voters in capital Kiev, some disillusioned, some hopeful started to arrive at polling stations early in the
"I don't expect anything from this election. It will not change anything neither for me as a citizen, nor for the country in general," said Kiev resident Nina who was one of the first to vote.
"Everyone hopes for the better me including ... I hope we will elect deputies who are decent and respectful of our nation," said Mykhailo Symonenko, another early voter.
Opinion polls suggest that Yanukovych's alliance with the Communist Party and a top centrist politician will retain its narrow lead, while Tymoshenko's opposition bloc will grab second place by the slimmest of margins.
But trailing in hot pursuit in third is the UDAR (Punch) party of Klitschko - an opposition sympathiser who has served in the Kiev city council and now has the chance to expand nationally.
"What's attractive about Klitschko is that he doesn't have a past in politics. He speaks from the heart"
- Lilit Gevorgyan, IHS Global Insight
"I am confident that we will be able to gather all the opposition forces around us in the new parliament," he boldly predicted in an interview with a German newspaper on the eve of the vote.
Klitschko has insisted that he can work with Tymoshenko's alliance. But he has fought bitterly with other members of the potential coalition and has thus far refused to sign any formal agreement forming an official anti-Yanukovych bloc.
An alliance between UDAR and the Tymoshenko bloc could give the opposition a parliamentary majority and further limit the political options of Yanukovych, already under heavy pressure from the West.
Lilit Gevorgyan, a Central Asia Analyst at IHS Global Insight, said the rise of Klitschko shows how disappointed voters are with both the opposition and the ruling coalition, thinking they have not delivered on their promises.
"What's attractive about Klitschko is that he doesn't have a past in politics," she told Al Jazeera. "He speaks from the heart. To some Ukrainians it appears that he's an absolutely honest and genuine guy and that's why they support him."
Half of the 450 seats will be filled with voters casting ballots for parties that have to clear a five-per cent minimum vote threshold. The remainder is comprised of votes for individual candidates who must win their districts to get in.
|Opinion polls suggest that Yanukovych's alliance
will retain its majority after the vote [Reuters]
The vote was preceded by an extremely rare joint letter from US Secretary of State Hillary Clinton and EU foreign policy chief Catherine Ashton calling on Yanukovych to prove his democratic credentials to the world.
"Important steps now have to be taken by the Ukrainian government to fulfil its full potential," the open letter said.
More than 3,700 foreign observers are in Ukraine to monitor the vote.
Al Jazeera's Rory Challands, reporting from Kiev, said major incidents of election fraud were unlikely, partly due to the large presence of monitors but also because the competing parties have an interest in the vote being perceived as fair and transparent.
"Pretty much all the parties here, even the incumbent party, have a strong vetted interest in making sure these elections are as transparent as possible and that the European monitors, and the EU, which is watching this very closely, are satisfied," he said. "Ukraine's' relationship with the EU is very important and most political forces here want it to be as good as possible."
In a message posted on her website, Tymoshenko urged voters to cast their ballots despite her forced absence from the polls.
"Your mass turnout can help overcome ballot rigging," she said. "This will be your personal contribution to the removal of Yanukovych from power."
Tymoshenko has been jailed through 2018 and is facing new charges related to fraud and tax evasion. There is also a separate murder investigation in which she has featured as a witness.