Georgians are going to the polls to decide whether to end 12 years of increasingly authoritarian rule, in an election that will decide their future path towards the European Union.

Georgia borders Russia and the governing Georgian Dream party is accused by the opposition of moving away from the West and back into Russia’s orbit. The EU has frozen Georgia’s EU bid because of “democratic backsliding”.

“I voted for a new Georgia,” said pro-Western President Salome Zourabichvili.

Saturday’s vote has been described as the most crucial since Georgians backed independence from the Soviet Union in 1991. There were reports of scuffles and vote violations as tempers flared at polling stations.

About 3.5 million Georgians are eligible to vote until 16:00 GMT in this high-stakes election that the opposition is calling a choice between Europe or Russia, but which the government frames as a matter of peace or war.

Georgian Dream is widely expected to come first, but four opposition groups believe they can combine forces to remove it from power and revive Georgia’s EU process.

Four out of every five voters are said to back joining the EU in this South Caucasus state, which fought a five-day war with Russia in 2008.

It was only last December that the EU made Georgia a candidate. But that process was halted after the government passed a Russia-style law that requires groups to register as “pursuing the interests of a foreign power” if they receive 20% of funding from abroad.

Politics here has become increasingly bitterly polarised, as Georgian Dream, under the guiding force of Georgia’s richest man, Bidzina Ivanishvili, seeks a fourth term of power.

If Ivanishvili’s party wins a big enough majority, he has vowed to ban opposition parties, notably the biggest, the United National Movement.

Georgian Dream, known as GD, is set to win about a third of the vote according to opinion polls, although they are widely seen as unreliable. If GD is to be unseated, all four of the main opposition groups will have to win upwards of 5% of the vote to qualify for the 150-seat parliament.

Ivanishvili’s rhetoric has become increasingly anti-Western and, after voting in Tbilisi, he told reporters that Georgians had a simple choice of either a government that served them, or an opposition of “foreign agents, who will carry out only the orders of a foreign country”.

President Zourabichvili has been outspoken in her backing for a broad opposition coalition government to end “one-party rule in Georgia”. As she voted she said there would be people “who are victorious, but no-one will lose”.

She has agreed a charter with the four big groups so that if they win, a technocrat government will fill the immediate vacuum. It would then reverse laws considered harmful to Georgia’s path to the EU and move to snap elections.

Tina Bokuchava, who’s chair of the biggest opposition party, United National Movement, insists all credible polls put the opposition ahead.

But while Georgian Dream tells voters they are still on course to join the EU, it has also warned them an opposition victory will trigger war with Russia.

Party billboards show split pictures of devastated cities in Ukraine alongside tranquil Georgia, with the slogan: “No to war! Choose peace.”

GD claims the opposition will help the West open a new front in Russia’s war in Ukraine, while Georgian Dream will keep the peace with its Russian neighbour, which still occupies 20% of its territory after the 2008 war.

Although the governing party’s claim is unfounded and its billboards have been widely condemned, its message appears to have got through.

In Kaspi, an industrial town to the north-west of Tbilisi, one woman aged 41 told the BBC: “I don’t like Georgian Dream, but I hate the [opposition United] National Movement – and at least we’ll be at peace.”

Another woman called Lali, 68, said the opposition might bring Europe closer, but they would bring war too.

Election observers have reported a number of violations at polling stations, including ballot stuffing and a physical attack on an opposition political figure in Marneuli, south of Tbilisi.

The International Society for Fair Elections and Democracy said almost one in 10 of their observers had reported violations at polling stations. On the eve of the vote it said people’s ID cards had been seized, and pointed to Russian-sponsored disinformation operations.

The BBC spoke to one voter, Aleksandre, in a village north-west of the capital who said he had been threatened by a local GD man with losing his job if he did not sign up to vote for Georgian Dream: “I’m a bit scared of his threat but what can I do?”

Georgian Dream maintains it has made elections more transparent, with a new electronic system for vote counting.

“For 12 years we have an opposition that questions the legitimacy of Georgia’s government constantly. And that’s absolutely not a normal situation,” says Maka Bochorishvili, GD’s head of the parliament’s EU integration committee.

Critics say in some places there is a genuine fear that the vote is not really secret.

“All this speculation about forcing people to vote for certain political parties – at the end of the day you’re alone and casting your vote, and electronic machines are counting that vote,” said Bochorishvili.

Not far from the centre of Tbilisi, Vano Chkhikvadze points to graffiti daubed in red on the walls and ground outside his office at the Civil Society Foundation.

After the “foreign influence” law was passed, in the face of mass protests in the centre of Tbilisi and other big cities, he says he was personally labelled by Prime Minister Irakli Kobakhidze as a state traitor.

“We were getting phone calls in the middle of the night. Our kids even were getting phone calls. They were threatened.”

Ahead of the vote, the EU warned that Georgian Dream’s actions “signal a shift towards authoritarianism”.

Whoever wins, the loser is unlikely to accept defeat easily.