Serbia’s ruling populists have claimed a sweeping victory in the country’s parliamentary election, which have been marred by reports of major irregularities both during a tense campaign and on voting day.

Prime Minister Ana Brnabic said that with half of the ballots counted, the Serbian Progressive Party’s projections show that President Aleksandar Vucic won 47% of the vote and expects to hold around 130 seats in the 250-member assembly.

The main opposition Serbia Against Violence group won around 23%, Ms Brnabic said.

The main contest in the parliamentary and local elections on Sunday was between Mr Vucic’s governing Serbian Progressive Party, or SNS, and a centrist coalition that is trying to undermine the populists who have ruled the troubled Balkan state since 2012.

The Serbia Against Violence opposition coalition of parties was expected to mount the biggest challenge for the city council in Belgrade, where the vote count was expected late in the night.

An opposition victory in the capital would seriously dent Mr Vucic’s hardline rule in the country, analysts said.

Turnout one hour before the polls closed was around 55%, about the same as during the last election in 2022 when Mr Vucic scored a sweeping victory.

Irregularities were reported by election monitors and independent media during the vote on Sunday, including ethnic Serbs from neighbouring Bosnia gathering to vote at a sports hall in Belgrade that was not an official polling station and a monitoring team attacked and their car bashed with baseball bats in a town in northern Serbia.

Observers from the independent Centre for Research, Transparency and Accountability expressed “the highest concern” over cases of the organised transfer of illegal voters from other countries to Belgrade, the group said in a statement.

“The concentration of buses, minivans and cars was observed on several spots in Belgrade, transferring voters to polling stations across the city to vote,” the group said.

CRTA also reported cases of voters being given money to vote for the governing party and the presence of unauthorised people at polling stations.

Authorities disputed that there was any wrongdoing. Ms Brnabic, the premier, called the accusations “lies that are intended to spread panic”.

Several right-wing groups, including pro-Russia parties and Socialists allied with Mr Vucic, ran candidates for parliament and local councils in around 60 cities and towns as well as regional authorities in the northern Vojvodina province.

The election did not include the presidency, but governing authorities backed by dominant pro-government media ran the campaign as a referendum on Mr Vucic.

Although he was not formally on the ballot, the Serbian president campaigned relentlessly for the SNS, which appeared on the ballot under the name “Aleksandar Vucic — Serbia must not stop!”

The main opposition Serbia Against Violence, a pro-European Union bloc, includes parties that were behind months of street protests this year triggered by two back-to-back mass shootings in May.

The Serbian president toured the country and attended his party’s rallies, promising new roads, hospitals and one-off cash bonuses. Mr Vucic’s image was on billboards all over the country, though he had stepped down as SNS party leader.

Serbia, a Balkan country that has maintained warm relations with Russia and President Vladimir Putin, has been a candidate for European Union membership since 2014, but has faced allegations of steadily eroding democratic freedoms and rules over the past years.

Both Mr Vucic and the SNS denied allegations of campaign abuse and attempted vote-rigging as well as charges that Mr Vucic as president violated the constitution by campaigning for one party.

Hardly any of the complaints or recommendations by local and foreign observers resulted in changes in the voting process.

Mr Vucic called the early vote only a year-and-a half after a previous parliamentary and presidential election, although his party holds a comfortable majority in parliament.

Analysts said Mr Vucic is seeking to consolidate power after the two back-to-back shootings triggered months of anti-government protests, and as high inflation and rampant corruption fuel public discontent.

Mr Vucic has also faced criticism over his handling of a crisis in Kosovo, a former Serbian province that declared independence in 2008, a move that Belgrade does not recognise.

His supporters view Mr Vucic as the only leader who can maintain stability and lead the country into a better future.

“I think it’s time that Serbia goes forward with full steam,” retiree Lazar Mitrovic said after he voted. “That means that it should focus on its youth, on young people, education and of course discipline.”