By Richard Balmforth

KIEV (Reuters) - Ukraine opposition parties called a public rally for Monday to protest against what they said was fraud by President Viktor Yanukovich's ruling party in the final stages of the vote-count from the October 28 parliamentary election.

The united opposition, which includes the Batkivshchyna (Fatherland) party of jailed ex-prime minister Yulia Tymoshenko, issued its protest call with a handful of seats to the 450-seat parliament still in dispute between candidates favorable to Yanukovich's Party of the Regions or to opposition forces.

Over the weekend, nerves were at breaking point in several of nine disputed districts with election officials who were conducting the vote-count besieged by supporters from both camps, demanding a re-count or threatening court action.

In one district in southern Ukraine, black helmeted riot police used tear gas when tensions boiled over between representatives backing a Regions candidate and those supporting a Batkivshchyna member.

The Regions, seen as representing the interests of big business, still seem set to retain a majority of more than 225 seats in the assembly, assuming support from their traditional communist allies and some independents.

But Batkivshchyna has made a strong showing and the opposition will be re-energized by the arrival in parliament of the UDAR (Punch) party of world heavyweight boxing champion Vitaly Klitschko and the far-right nationalist Svoboda (Freedom) party.

An overall Regions victory is likely to be seen by Yanukovich as a mandate to continue policies which opponents say favor the big business industrialists who back him.

Equally, the leadership will continue to be cold-shouldered by the United States and the European Union over the imprisonment of Tymoshenko. The EU has already refused to settle a major free trade pact because of her case.

ORANGE REVOLUTION MEMORIES

Calls by the opposition for a protest rally in central Kiev over alleged vote-rigging evoke memories of the "Orange revolution" street protests of 2004-5 which overturned an election of Yanukovich as president, dooming his first bid for power.

"The authorities are carrying out bare-faced fraud in districts where opposition candidates are winning. The wishes of tens of thousands of citizens are being changed into a forged result in favor of pro-ruling party candidates," a united opposition statement said on Sunday.

"The united opposition is appealing to all opposition forces, to all those who are not indifferent to fate of the country, to come to the building of the central electoral commission and defend their vote," it said.

The Regions have denied allegations of vote-rigging.

International monitors, the day after voting, criticized the authorities over aspects of the run-up to the election, mentioning specifically Tymoshenko's imprisonment and biased media coverage.

They said the election marked a "step backwards" for Ukraine under Yanukovich's leadership, though they were largely positive about the way voting had been conducted.

External monitors have since been sharply critical of the way the counting of ballots was manually carried out across the former Soviet republic of 46 million.

The central election commission on Sunday said only three seats in individual constituencies still remained to be decided. But complaints about the official result in several others, mainly from the opposition, have gone to local courts and are awaiting adjudication.

Referring specifically to the way the count was conducted, an observer team from Canada last Friday reported evidence of deliberate attempts to manipulate results, particularly where competition was at its keenest in places like the capital Kiev.

"We ... note that the process of vote tabulation has been marred by serious violations, which raises doubts about the integrity of the results in several districts," said a statement by the team, which fielded 500 monitors.

In a joint statement in Brussels on Saturday, senior European Union officials expressed increasing concern that final results of the October 28 election had still not been announced.

EU foreign policy chief Catherine Ashton and EU Commissioner for Enlargement Stefan Fule urged authorities and parties "to take the necessary steps to finalize the tabulation allowing for the rapid announcement of the final results, which should reflect the genuine will of the Ukrainian voters."

Half of seats in parliament are awarded to candidates who win the most votes in individual constituencies, and half are given out proportionately to party lists.

Yanukovich's Regions have won 30 percent of the vote on party lists, with their traditional allies, the communists, taking 13 per cent. Together with gains in individual constituencies, this should add up to a comfortable majority.

In the opposition camp, Tymoshenko's Batkivshchyna bloc stood at 104 seats, Klitschko's UDAR at 40 and Svoboda at 37.

(Writing By Richard Balmforth)