German Chancellor Gerhard Schroeder and his rival Angela Merkel made a last push for votes on Saturday, hours before polls open in an election that will set the agenda for reform in Europe's largest economy.
Merkel, whose centre-right Christian Democrats (CDU) have consistently led the opinion polls, is expected to become Germany's first woman chancellor and the first to have grown up in the former communist east if her alliance wins Sunday's vote.
But it remains uncertain whether she will gain enough support to form the coalition she says is needed to push through deep-seated reform of Germany's sickly economy, or whether she will have to share power with Schroeder's Social Democrats.
The last opinion polls on Friday gave the CDU and their liberal Free Democrat (FDP) allies a narrow majority. Their earlier hefty lead has been cut sharply by a barnstorming campaign effort from Schroeder.
Both leaders spoke at campaign rallies on Saturday as the main parties have defied tradition and pledged to fight for every vote right up until the close of polling.
"It's about making sure everyone's voice counts, my own included," Schroeder, his raucous voice cracking with the strain of campaigning, joked to a 20,000-strong crowd in Germany's financial capital, Frankfurt.
With recent surveys showing as many as 10 million voters, apparently yet to make up their minds, anything may happen by the time voting ends at 6 pm (1600 GMT) on Sunday, when first exit polls are due.
"At 20 percent plus two days before the election, the number of undecided is higher than before any other general election," Richard Hilmer, head of pollsters Infratest Dimap told the daily Die Welt on Saturday.
The levels were testament both to what is at stake and the deep uncertainty many Germans feel about the future course of their country.
Five million people are out of work, the pensions system is facing crisis, schools and universities are in urgent need of investment and reform, while some firms have stopped complaining about high costs and have instead shifted operations abroad.
Surveys suggest most Germans accept the system needs to change but are uncertain about how far and how fast, a dilemma facing other European countries with similar welfare states.
Restoring growth to an economy that was once seen as Europe's motor but which has stuttered badly in recent years will also be vital.
"This means that the German election outcome will be the most important in decades not just for Germany but for Europe as a whole," Barclays Capital economists Julian Callow and Thorsten Polleit wrote this week.
Schroeder's own "Agenda 2010" reforms have already begun to change the system in ways unimaginable a decade ago, much to the anger of many in his own party who feel the brunt of change has been borne by the less well-off.
But Merkel says he is no longer capable of governing. "We can do it better. I'm deeply convinced of that," she told a rally in the former capital, Bonn.
Inevitably, policy issues have been obscured as the rival campaigns have exchanged accusations of lying and deception.
But the stark personal contrast between the candidates has symbolised clearly the choice facing Germany.
Apparently at the end of his political career, Schroeder stood on his record of keeping Germany out of the Iraq war, appealed to Germans' deep attachment to the principle of social balance and attacked conservatives as cold friends of the rich.
Determined but less charismatic, Merkel has accused him of botching his own reforms.
She has pledged to raise value-added-tax and cut wage costs, loosen hiring and firing rules and open up Germany's pay bargaining system in a move that would weaken the power of the unions, saying only more jobs can ensure social justice.