Ukraine's ruling party has claimed victory in parliamentary elections international monitors said was reversing earlier democratic gains the country has made.
Mykola Azarov, the current prime minister, said President Viktor Yanukovych's Party of the Regions would win the majority of seats after Sunday's vote.
"It is clear the Party of the Regions has won," Azarov said on Monday. "These elections signal confidence in the president's policies."
The poll was seen as a test for Ukraine's democracy amid the criticism of the imprisonment of former prime minister Yulia Tymoshenko on corruption charges.
The Party of the Regions had 35.03 per cent of the vote against 21.98 per cent for Tymoshenko's opposition party, the central election commission said with half the precincts reporting in the proportional system that will determine half the seats in the new parliament.
The pro-business ruling party was also on course to win at least 114 seats out of the 225 that are being determined by first-past-the-post single mandate constituencies, an early analysis of the results showed.
The Communists were polling strongly in third place with 14.9 per cent, followed by boxing champion Vitali Klitschko's new UDAR (Punch) party on 12.8 per cent.
The ultra-nationalist Svoboda (Freedom) party was also due to break the five per cent threshold needed to make parliament, according to the partial results.
The 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 the jailing of Tymoshenko, which has isolated Ukraine from European Union states.
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.
Opposition parties have alleged severe violations in Sunday's poll, including vote-buying, multiple voting and non-transparent vote counting, though authorities insisted that the vote was clean.
A monitoring team from the Organisation for Security and Co-operation in Europe said the vote was marred by the Party of the Regions using state resources and facilities for campaigning and by a lack of transparency over how parties were financed.
"The 28 October parliamentary elections were characterised by the lack of a level playing field caused primarily by the
abuse of administrative resources, lack of transparency of campaign and party financing and lack of balanced media
coverage," the OSCE mission said in a report.
"Certain aspects of the pre-election period constituted a step backwards compared with recent national elections," it
said, an apparent reference to Yanukovich's election in February 2010 which was judged fair by the West.
The OSCE statement said the inability of Tymoshenko to run as a candidate had also "negatively affected" the election process.
"One should not have to visit a prison to hear from leading political figures in the country," OSCE special co-ordinator Walburga Habsburg Douglas.
Al Jazeera's Rory Challands, reporting from Kiev, said two factors would determine how much dominant the ruling party would be in the new parliament.
"The first is whether the opposition can be unified," he said.
"Two parties that have won members of parliament for the first time ... They'll be trying to work as well as they can with Batkivshchyna, the party of Tymoshenko.
"Also key is whether the Party of the Regions will have an outright majority. If they do, it will be very, very easy for them to dictate the future policy of Ukraine."
Yanukovych's party strongly benefited from an electoral change it pushed through last year. Under the new law, the strictly proportional electoral system has been changed into a mixed one, in which half the Verkhovna Rada seats are elected based on party lists and the other half in individual races.
Yanukovych's candidates are stronger in those majority races, with the opposition fielding multiple candidates and the ruling party enjoying greater access to government funds and resources.