WARSAW — An exit poll for Poland’s presidential runoff on Sunday showed a race that was too close to call between the conservative, populist incumbent and the pro-Europe, liberal mayor of Warsaw — a battle that reflected the deep divisions in this European Union nation.
The Ipsos institute’s exit poll showed President Andrzej Duda with 50.4 percent of the vote and rival Rafal Trzaskowski with 49.6 percent. But the poll has a margin of error of plus or minus 2 percentage points, meaning it was not possible to say with certainty which 48-year-old candidate had won.
Long lines were visible at some polling stations Sunday night, forcing them to stay open past their official closing time of 9 p.m. for what many considered to be one of the most crucial elections in Poland’s three decades of democracy.
Another exit poll based on more data was to be published later Sunday with a tighter margin of error. Official results were not expected until Monday or Tuesday.
The result is expected to lead to starkly different political paths for Poland, at least until 2023, when the next parliamentary election is scheduled.
Duda, who is backed by the ruling right-wing Law and Justice party and the government, campaigned on traditional values and social spending in this mostly Catholic nation as he sought a second five-year term.
Trzaskowski, a former European Parliament lawmaker, jumped into the race relatively late to oppose Duda’s denigration of urban liberals, the LGBT community, and other minorities and to counter an erosion of democratic rights under the ruling party. He represented the centrist opposition Civic Platform party, which was in power in from 2007 to 2015.
If Duda is reelected, the populist Law and Justice party will keep a close ally in the president and maintain its hold on almost all key instruments of power in the nation of 38 million people.
A win for Trzaskowski would give him the power to veto laws passed by the ruling conservatives and give Poland a less contentious relationship with European Union officials.
Duda said the turnout was nearly 70 percent, which would be a record high for a presidential election in the 30 years since Poland threw off communism, embraced democracy, and later gained membership in NATO and the EU. If confirmed by election officials, the high turnout is a sign of the great importance that many Poles placed on Sunday’s vote.
Duda thanked his supporters and called the high turnout “a beautiful testimony of our democracy.”
To those who were supporting Trzaskowski, it was possibly a last chance to halt an erosion of the rule of law under Duda and the ruling party, both in power since 2015.
At an election night event, Trzaskowski said he still believed the numbers could turn in his favor. He did not say why, but the exit poll does not reflect the votes cast from abroad, and a majority of them were expected to go to Trzaskowski.
“All the votes just need to be counted which, in truth, will make this evening a nerve-wracking one for everyone in Poland,’’ Trzaskowski said. ‘‘But I am absolutely convinced when we count each vote, we will be victorious and we will definitely win.”
The balloting was supposed to be held in May but after much political wrangling was delayed by health concerns amid the coronavirus pandemic. Some 30 million voters were eligible to cast ballots. In the first round amid a dozen candidates, Duda got 43.5 percent support and Trzaskowski 30.5 percent.
The head of Poland’s Roman Catholic Church, Archbishop Wojciech Polak, said the new president should be conciliatory. “In the situation when we see constant discord, divisions, the rift in society, let him be a unifying one, the president of all Poles,” Polak said.