Thousands of opposition supporters took to the streets of Georgia's capital Tbilisi on Sunday to demand snap polls after the ruling Georgian Dream party claimed victory in a parliamentary vote.

The ex-Soviet nation's opposition rejected the results of Saturday's vote, which showed Georgian Dream with a narrow lead in the tightly contested election.

The demand for fresh elections could spark another political crisis in the Caucasus republic of four million, where elections are often followed by accusations of fraud and mass demonstrations.

Supporters of the United National Movement party hope to oust the Georgian Dream led by the country's richest man, Bidzina Ivanishvili
Supporters of the United National Movement party hope to oust the Georgian Dream led by the country's richest man, Bidzina Ivanishvili AFP / Vano SHLAMOV

Waving Georgian flags, demonstrators gathered outside the imposing parliament building on Tbilisi's main thoroughfare after exiled ex-president and opposition leader Mikheil Saakashvili called for protests.

The crowd, many wearing masks against the coronavirus, burst into applause as opposition leaders said the vote had been rigged and demanded a new election.

"All of Georgia's opposition parties are united in the decision not to enter the new parliament," Nika Melia, one of the leaders of Saakashvili's United National Movement (UNM), told the rally.

"We will be fighting until the goal (of a new election) is achieved," he said, announcing another protest for next Sunday.

Georgia's former Prime Minister Bidzina Ivanishvili is a billionaire and leader of the incumbent Georgian Dream
Georgia's former Prime Minister Bidzina Ivanishvili is a billionaire and leader of the incumbent Georgian Dream AFP / VANO SHLAMOV

"We will not let Georgian Dream steal our votes," one of the demonstrators, 54-year-old accountant Tornike Meladze, told AFP. "Protests will go on until new elections are called."

With votes from nearly all precincts counted, Georgian Dream had won 48 percent of the proportional vote, against 45.6 percent for opposition parties.

Campaign posters are everywhere in the Georgian capital Tbilisi
Campaign posters are everywhere in the Georgian capital Tbilisi AFP / Vano Shlamov

The proportional vote decides 120 of the 150 seats in the legislature.

Georgian Dream's leader, billionaire ex-prime minister Bidzina Ivanishvili, said his party "has won elections for the third time in a row" and "elected a great team".

Prime Minister Giorgi Gakharia said on Twitter that the election had been "another important milestone in Georgia's democratic development."

International monitors from the Organisation for Security and Cooperation in Europe (OSCE) and the NATO Parliamentary Assembly said the vote was "far from flawless" but that "fundamental freedoms were respected".

Voter protection: A woman  receives her ballot form at a polling station in Tbilisi on Saturday
Voter protection: A woman receives her ballot form at a polling station in Tbilisi on Saturday AFP / Vano SHLAMOV

Local election observers were harsher, reporting numerous cases of ballot stuffing, multiple voting and doctoring of results.

Independent election watchdog ISFED said in some precincts the number of votes awarded to the ruling party was higher than the number of ballots cast.

The polls "marked a setback of Georgia's democracy," the Georgian branch of Transparency International said, while watchdog GYLA said "election day was marred by... serious violations".

Georgia became a darling of the West after Saakashvili came to power in the 2003 Rose Revolution and instituted reforms to boost democratic institutions and battle corruption.

But a 2008 war with Russia and political infighting has dimmed hopes of the country joining NATO and the European Union.

Georgian Dream -- widely seen as a vehicle for Ivanishvili's political ambitions -- emerged in 2012 to dominate the country's politics.

Georgia remains one of the most pluralistic countries to emerge from the 1991 collapse of the Soviet Union, although concerns have been growing that it is backsliding on democracy.

In an unprecedented show of unity before the vote, Saakashvili's UNM and smaller opposition groups joined forces and held talks on forming a coalition government if elected.

With another 30 seats to be assigned in single-mandate constituencies requiring up to two rounds of voting, the final makeup of the new parliament may only become clear in late November.

Saakashvili was forced to flee Georgia at the end of his second term as president in 2013, fearing arrest after prosecutors accused him of abusing power -- charges he has denied.

Western capitals have accused the Georgian Dream-led government of mounting a political witch-hunt against the ex-president and his allies.

Tbilisi-based analyst Gela Vasadze said Georgia appeared headed for a period of political uncertainty, even if the opposition fails to bring out big crowds of protesters.

"Georgian Dream will have an extremely shaky majority in the new parliament," he said.