By Richard Balmforth
KIEV (Reuters) - Jailed opposition leader Yulia Tymoshenko made an impassioned call to Ukrainians on Thursday to throw out President Viktor Yanukovich's ruling party on Sunday and stop a "dictatorship" which she warned would isolate Ukraine.
Tymoshenko's plea added to tension ahead of a parliamentary election in which Yanukovich's Party of the Regions is seeking to hold on to its majority against a divided opposition, weakened by her imprisonment.
No opinion polls have been published in the former Soviet republic since October 18 in line with an official information black-out.
But ratings before then showed the Regions with a firm lead over opposition parties which include Tymoshenko's Batkivshchyna (Fatherland) and a new liberal party headed by heavyweight boxing champion Vitaly Klitschko.
The government is unpopular because of its tax and pension policies. But most commentators expect the Regions, which is bankrolled by Ukraine's wealthiest industrialists, to hold on to its majority in the 450-seat assembly, cementing the leadership of Yanukovich who comes up for re-election as president in 2015.
Tymoshenko, a former prime minister and the country's most vibrant opposition leader, is serving a seven-year jail sentence for abuse of office which the United States and the European Union have denounced as "selective justice" and see as political vengeance by Yanukovich.
In a statement read out by her daughter Yevgenia, the 51-year-old Tymoshenko, a political firebrand in her heyday, described Sunday's election as a "war which can end with your victory and a chance for change or with our total historical failure."
"If, thanks to your votes, Yanukovich survives as a politician in these elections, he will establish a dictatorship and will never again give up power by peaceful means," she said.
Indicating that a year in prison had not dimmed her powers of oratory, she said Yanukovich's rule would be like a blaze tearing through every family and every company, engulfing freedom and "isolating Ukraine from the rest of the world".
The EU shelved landmark agreements on free trade and political association with Ukraine after Tymoshenko was sentenced a year ago. On indifferent terms with Russia too, many commentators see Ukraine as being adrift in a grey no-man's land between Moscow, Brussels and Washington.
Of the 450 seats in the single-chamber parliament, 225 will be filled through voting by party lists, in which the voter casts a ballot for a party which presents a list of candidates.
The other half will be filled by voting for individual candidates in electoral districts - a feature re-introduced by the present parliament and one which is assumed to favor the Regions.
The united opposition, led by former economy minister Arseny Yatesnyuk in the absence of Tymoshenko, and Klitschko's UDAR (Punch) party, say they expect the Regions to use its fatter wallet to bribe voters across the country. The Regions deny accusations of unfair campaigning.
Tymoshenko, in her statement, called on the electorate to resist attempts to buy their support. "If you want to survive, you will have to take yourselves by the throat and refuse to swallow any material hand-outs," she said.
She also warned voters against casting their ballot for phantom parties masquerading as opposition but in reality representing the interests of the ruling party.
She appeared to be referring to politicians such as Natalia Korolevska, who left Tymoshenko's party last year and formed her own "Ukraine-Forward" party, enlisting national football hero Andriy Shevchenko onto her ticket.
Though Korolevska's press service says the party is in opposition, commentators say it is financed by an industrialist who bankrolls also the Regions and is intended to siphon off support from the real opposition.
The election will be monitored by about 3,800 international observers and some 240,000 local observers.
In a joint article published on October 24 by the New York Times, U.S. Secretary of State Hillary Clinton and EU foreign policy chief Catherine Ashton said the West was concerned at Tymoshenko's continued imprisonment, and at reports that state resources were being used to promote Regions' candidates.
(Additional reporting by Pavel Polityuk; Writing By Richard Balmforth; Editing by Stephen Powell)