Polls have closed in the Brazilian presidential run-off that pits an incumbent vowing to safeguard conservative Christian values against a former president promising to return the country to a more prosperous past.

The run-off shaped up as a close contest between President Jair Bolsonaro and his political nemesis, former president Luiz Inacio Lula da Silva. Both are well-known, divisive political figures who stir passion as much as loathing.

The vote will determine if the world’s fourth-largest democracy stays on the same course of far-right politics or returns a leftist to the top job — and, in the latter case, whether Mr Bolsonaro will accept defeat.

There were multiple reports of what critics said appeared to be attempts to suppress turnout of Lula voters.

Polling stations in the capital, Brasilia, were already crowded by morning and, at one of them, retired government worker Luiz Carlos Gomes said he would vote for Mr Da Silva.

“He’s the best for the poor, especially in the countryside,” said Mr Gomes, 65, who hails from Maranhao state in the poor north-east region. “We were always starving before him.”

Because the vote is conducted electronically, the final result is usually available within hours after voting stations close in late afternoon. Most opinion polls gave a lead to Mr da Silva, universally known as Lula, though political analysts agreed the race grew increasingly tight in recent weeks.

For months, it appeared that Mr Da Silva was heading for an easy victory as he kindled nostalgia for his 2003-2010 presidency, when Brazil’s economy was booming and welfare helped tens of millions join the middle class.

But while he topped the October 2 first-round elections with 48% of the vote, Mr Bolsonaro was a strong second at 43%, showing opinion polls significantly underestimated his popularity. Many Brazilians support Mr Bolsonaro’s defence of conservative social values and he has shored up support with vast government spending.

Candidates in Brazil who top the first round tend to win the run-off. But political scientist Rodrigo Prando said this campaign is so atypical that a Bolsonaro win could not be ruled out.

More than 150 million Brazilians are eligible to vote, yet about 20% of the electorate abstained in the first round. Both Mr da Silva and Mr Bolsonaro have focused efforts on driving turnout.

The electoral authority prohibited any federal highway police operations from affecting voters’ passage on public transport.

Still, there were multiple reports of checkpoints and traffic stops. Television network Globo reported more than 500 stops, half of which were in the north-east region, a Workers’ Party stronghold. The party filed a request for the arrest of the highway police’s director, and demanded the region’s polls remain open later.

Human Rights Watch, an international non-profit organisation, said in a statement it was “very concerned” about the reports.

Speaking to reporters in Brasilia, the electoral authority’s president Alexandre de Moraes said the police force’s director had provided clarification that no stop lasted over 15 minutes, turnout was not affected and polls would close at 5pm local time, as scheduled.

“(Stops) were made in accordance with traffic laws and that stalled some voters, but all arrived to their voting places. No bus returned to its point of origin,” said Mr De Moraes, adding that all traffic stops have since been suspended.