A partial ballot recount in Georgia's contested parliamentary election has confirmed the ruling party won, electoral officials said on Thursday, after opposition parties disputed the results and Washington and Brussels demanded an investigation.

A spokesperson for Georgia's electoral commission said final tallies after the partial recount "only slightly changed at some nine per cent of recounted polling stations" compared to the initial count.

Georgia plunged into political uncertainty following Saturday's election as the pro-Western opposition said the vote was "stolen" by the ruling Georgian Dream party and refused to recognise its results.

Pro-European President Salome Zurabishvili — at loggerheads with the governing party — has declared the election results "illegitimate", alleging election interference by a "Russian special operation".

Tens of thousands took to the streets on Monday to protest against alleged fraud.

International observers, the European Union and the United States have denounced electoral irregularities and demanded a full investigation.

The European Commission warned in a report published on Wednesday that it could not recommend opening membership talks "unless Georgia reverts the current course of action which jeopardises its EU path".

Georgia's interior ministry said two people were arrested following alleged ballot stuffing at a provincial polling station, while prosecutors said they had opened 47 criminal cases over alleged electoral violations.

On Wednesday, Georgian prosecutors said they had summoned President Salome Zourabichvili for questioning, because she "is believed to possess evidence regarding possible falsification".

But the figurehead president refused the summons, saying that plenty of evidence of electoral fraud was already available and prosecutors should focus on their investigation and "stop political score-settling with the president".

Opposition parties have said they will not enter the new "illegitimate" parliament and demanded "fresh" elections.

AFP