By Felix Light
TBILISI (Reuters) -Two U.S. pollsters commissioned by Georgian opposition forces called into question official results that showed the governing Georgian Dream party won last weekend's parliamentary election in the South Caucasus country, as opposition parties prepared to hold a new protest next week.
U.S. data and polling firm Edison Research, commissioned by the pro-opposition television channel Formula, said the differences between its own exit poll and the official results pointed to "manipulation" of the vote.
On Thursday, HarrisX, another U.S. pollster that ran an exit poll for pro-opposition television channel Mtavari Arkhi, said the official results were "statistically impossible".
Widely seen as pivotal for the former Soviet republic, the election offered a choice between further European integration under the pro-Western opposition, or closer ties with Moscow under a governing party that critics say is increasingly authoritarian.
Observer groups, including the 57-nation Organization for Security and Co-operation in Europe, have said violations such as ballot-stuffing, voter intimidation and bribery could have swayed the election, but stopped short of saying it was outright stolen. Russia has denied interfering in the election.
Both HarrisX and Edison had predicted that Georgia's four main opposition parties would together have a parliamentary majority. A third exit poll, carried out by Georgian pollster GORBI for the pro-government Imedi television station, predicted Georgian Dream would take 56% of the vote.
Georgia's pro-Western president has denounced the election as fraudulent and thousands gathered after the vote in Tbilisi, the capital, to express their discontent and are due to do so again on Monday.
Georgia's electoral commission has said the ruling Georgian Dream party, seen as being controlled by billionaire founder Bidzina Ivanishvili, won with 54% of the vote.
Georgian Dream, which has deepened ties with Russia while angering the West by passing laws Washington and Brussels do not like, says the election was free and fair.
POLLSTERS' CRITICISM
Edison Research's own exit poll showed Georgian Dream taking only 41% of the vote.
"The 13-point difference between Edison’s estimate and the official result of 54% for Georgian Dream cannot be explained by normal variation alone and suggests local-level manipulation of the vote," it said in a statement.
It "found that the deviation from statistically expected results was widespread but most pronounced at specific polling locations in rural areas."
These sites were the most likely to have experienced significant vote manipulation, it said.
Georgian Dream underperformed in larger cities, but drew margins of up to 90% in some rural areas.
Georgian Dream and the election panel did not immediately comment on the pollsters' statements.
On Thursday, HarrisX, another U.S. pollster, also questioned the results.
"We see statistically unexplainable discrepancies amounting to over 8 percent of the total vote, or at least 172,523 raw votes, across a minimum of 27 districts," it said.
According to the electoral commission, Georgian Dream received 1.12 million votes, outpolling the four main opposition parties combined by 335,000 votes.
In Marneuli, a heavily ethnic Azeri district south of Tbilisi where authorities confirmed instances of ballot-stuffing and violence on election day, HarrisX's exit poll gave the ruling party only 40% of the vote. Official results ultimately gave it 80% there.
Georgian state prosecutors say they have launched an investigation into allegations of falsification after Western countries called for a probe.