Ukrainian President Viktor Yanukovich's pro-business party seemed likely to hold on to a majority in parliament after an election on Sunday, but it will face a revitalised opposition boosted by a resurgent nationalist party, exit polls showed.
Leaders of the Party of the Regions claimed victory after two exit polls put it in the lead with between 28 percent and 30.5 percent of the voting in the part of balloting conducted by party lists.
A senior Regions leader said he expected the party to pick up two thirds of the remaining vote in individual districts, ensuring it of a simple majority in the 450-seat assembly.
But the big surprise came from the Ukrainian nationalist party Svoboda (Freedom) which exit polls said appeared certain of winning representation in parliament for the first time after taking around 12 per cent of the party list voting.
Svoboda's strong showing boosted opposition ranks, which include the Batkivshchyna (Fatherland) party of Yanukovich's jailed opponent Yulia Tymoshenko and the UDAR (Punch) party of boxing champion Vitaly Klitschko.
But though these three opposition parties appeared to have won roughly half of the vote on party lists, they were not expected to fare as well in the single-mandate constituencies, results of which will only begin to emerge on Monday.
There were no immediate available figures for how this would translate into seats in the 450-member single-chamber parliament.
But Borys Kolesnikov, a deputy prime minister, said he foresaw the Regions dominating in single-mandate constituencies. "There are 225 single-seat constituencies and we see our candidates winning 2/3 of them," he said.
"The exit poll data speaks for itself. It is clear the Party of the Regions has won... These elections signal confidence in the President's policies," Prime Minister Mykola Azarov told journalists.
Victory by the Regions is certain to cement the leadership of Yanukovich, who comes up for re-election in 2015 and whose rule has been marked by an accumulation of presidential powers and antagonism with the West over Tymoshenko's imprisonment.
Tymoshenko, the country's most vibrant opposition figure, was jailed for seven years last year for abuse of office relating to a 2009 gas deal with Russia which she made when she was prime minister. The Yanukovich government says the agreement saddled Ukraine with an enormous price for gas supplies.
The former Soviet republic of 46 million is more isolated internationally than it has been for years. Apart from being at odds with the United States and the European Union over Tymoshenko, Ukraine does not see eye to eye with Russia which has turned a deaf ear to Kiev's calls for cheaper gas.
At home, the government is also blamed for failing to stamp out corruption and has backed off from painful reforms that could secure much-needed IMF lending to shore up its export-driven economy.
With the West seeing the poll as a test of Ukraine's commitment to democracy, interest will focus on the judgment which observers from the OSCE European security and human rights body will hand down on Monday.
A positive assessment could improve Yanukovich's image before Ukraine takes over the organisation's chair in January.
Arseny Yatsenyuk, head of the united opposition in the absence of Tymoshenko, said: "The exit poll results have shown that the people of Ukraine support the opposition and not the government."
If the exit polls are proven accurate, Klitschko, the WBC heavyweight boxing champion, will now enter parliament at the head of his new party after a campaign in which he has been critical of corruption and cronyism under Yanukovich's rule.
He says his party will team up with Yatsenyuk and other members of the opposition, including the Svoboda party of Oleh Tyahnybok, a 43-year-old surgeon, which burst onto the scene on Sunday.
"We do not foresee any joint work with the Party of the Regions and its communist satellite. We are ready to work with those political parties which propose a European path of development," Klitschko told journalists.
Svoboda, based mainly in western Ukraine, is fiercely anti-Russian and promotes the use of the Ukrainian language in the country.
It is at the opposite end of the political spectrum from Yanukovich's Regions, which draws much of its support from Russian-speaking regions of the east and south.
"Svoboda is the biggest sensation," said political analyst Volodymyr Fesenko of the Penta think tank. "The Ukrainian political borsch (soup) has got a bit more spicy. There will be more pepper but how it is going to taste is another question," he said.
Fesenko added that he saw the vote for Svoboda as reflecting a protest against the political establishment.