Both Social democrats (SPD) and CDU/CSU bloc on track for 25 percent of vote in German election, exit polls showed.
Chancellor Angela Merkel's conservatives and the centre-left Social Democrats are running neck and neck in Sunday's vote to decide her successor, exit polls showed, in one of the most unpredictable elections in Europe's biggest economy in recent decades.
Surveys published on public television after polling stations closed at 1600 GMT (6 PM) found Merkel's Christian Democrats and their candidate Armin Laschet with around 24-25 percent of the vote, nearly tied with the Social Democrats on 25-26 percent.
Given the high proportion of voters who mailed in their ballot, the final results could still turn up surprises in the course of the night.
Sunday's epochal election ushers in the end of 16 years in power for Merkel, and also thrusts Germany, a byword for stability, into a new period of political uncertainty.
If there is little to set the two leading parties apart, both the CDU-CSU and the SPD could separately seek to form governing coalitions in a scramble for power – a lengthy process that could blunt Germany on the international stage for some time.
Olaf Scholz, the chancellor candidate for the centre-left Social Democrats, hailed a "great success" for his party after estimates showed his SPD narrowly ahead of the conservatives.
"It's going to be a long election night, that's for sure," Scholz said.
"But this is certain: many citizens have put their crosses next to the SPD because they want there to be a change in government and also because they want the next chancellor to be called Olaf Scholz."
Election to determine 'direction of Germany'
Voting earlier in their respective constituencies, Laschet, 60, of the CDU-CSU stressed that "every vote counts" in an election that would determine "the direction of Germany in the next years", while Scholz said he hoped summery weather was "a good sign" for his party.
The SPD, Germany's oldest party, were polling so badly just a few months back that many had written off the possibility that it may even be in the next government.
But Scholz, a colourless but competent former mayor of Hamburg, now stands a chance of becoming the first SPD chancellor since Gerhard Schroeder, who lost to Merkel in a close contest in 2005.
Rather, it would be the conservatives who are headed for their worst score post-war even though their candidate Laschet had gone into the race in the summer as the clear favourite to grab the top job in Europe's biggest economy.
But his popularity began to wane after a series of blunders over the summer, including being caught on camera laughing in the background during a tribute to the victims of devastating floods in Germany.
In the meantime, Scholz, who at the start of the year had looked down and out in the race, saw his ratings begin to rise as he avoided making such embarrassing mistakes.
With polls predicting a devastating defeat for Laschet, the conservatives trotted out their biggest asset -- Merkel.
Although she had originally planned to keep a low profile in the campaign, she found herself dragged into Laschet's frantic tour across the country to canvas for last votes -- something that has helped the CDU-CSU to stem a drop in popularity in the last days of the campaign.
Meanwhile, although climate change had been one of the top concerns among voters in the run-up to the vote, it has not translated into a sweep for the ecologist Greens.
The Green party enjoyed a surge in support earlier this year after naming 40-year-old Annalena Baerbock as its chancellor candidate, at one point even briefly taking the lead as the most popular party.
But after a series of missteps by Baerbock, including a plagiarism scandal, the Greens were polling well behind the two leading parties on around 17 percent.
While the chancellery may be out of reach for the party, it will likely have a role in Germany's next government.
All bets are off on the composition of the next coalition, as the SPD and the conservatives could each try to cobble together a ruling majority if there is little to divide their score.
On the eve of the polls, Scholz voiced his preference for a partnership with the Greens, calling on voters to give him the score needed to go with a two-way coalition.
Laschet has signalled he could still try to form a coalition even if the CDU-CSU do not come first, most likely calling on the Greens and the liberal FDP for support.
But coming in second would still be a devastating blow for the party, which has dominated German politics since World War II and has never won less than 30 percent of the vote in federal elections.
Merkel in office till new government formed
Merkel has been in power since 2005 but plans to step down after the election, making the vote an era-changing event to set the future course of Europe's largest economy.
Without an outright majority, many governing coalitions are mathematically possible, and that could trigger weeks or months of haggling to form a new government.
Until it is in place, Merkel will remain in office on a caretaker basis. Merkel has won plaudits for steering Germany through several major crises.
Her successor will have to tend the recovery from the coronavirus pandemic, which Germany so far has weathered relatively well thanks to large rescue programs that have incurred new debt.