BERLIN (Reuters) - Voting began in Germany's closely fought election on Sunday with millions of undecided voters holding the key to a result that will have major implications for economic reform in Europe.
Christian Democrat challenger Angela Merkel is expected to emerge as Germany's first woman chancellor, displacing Gerhard Schroeder who has led Germany for seven years at the head of a centre-left government of Social Democrats (SPD) and Greens.
But with unprecedented numbers of voters apparently undecided on the eve of the vote, it was unclear whether she could muster enough support to form the centre-right coalition government she says is needed to push through deep reforms of Germany's ailing economy.
"I was very confused over how to vote. It's never been so hard to decide," said Bettina Quentin, 39, a health worker casting her vote at a school in the east of Berlin.
"Unemployment and health policy were the most important issues for me. In the end I voted for the politicians I trust most. But I don't trust them 100 percent," she said.
If Merkel cannot form the ruling alliance she wants, she will probably be forced to share power with Schroeder's SPD in a "grand coalition" that markets fear would produce gridlock and stall the reforms that Schroeder himself began and Merkel wants to accelerate.
For Germany and the rest of Europe, the stakes are high and for a new leader, the problems will be daunting.
Some five million Germans are out of work, the country's pensions system is close to crisis, its public finances are overstretched and the economy that once drove growth in Europe is now lagging the rest of the continent.
Analysts say that if Germany succeeds in pushing through reforms, they could be a model for change in the rest of Europe.
Surveys show that most Germans believe the system needs changing but they are deeply uncertain about how far the changes should go and how the burden should be shared.
On Sunday morning, the area around the German parliament was packed with broadcast trucks and camera crews setting up equipment before polls close and the first exit polls are announced at 6 p.m. (1600 GMT).
A provisional result is expected in the early hours of Monday but if it's close, a final decision could depend on one district in the eastern city of Dresden where polling has been delayed until Oct. 2 because of the death of a candidate.
For Merkel, a quietly determined 51 year-old from the formerly communist east, victory would make her one of the most powerful leaders in Europe 15 years after she entered politics following the fall of the Berlin Wall.
But Schroeder, 61, has thrown himself into campaigning with a drive that has rocked his opponents and raised the possibility that the SPD may be able to salvage something from the election even if he himself steps down.
His "Agenda 2010" reforms to welfare and labour market rules have been the most ambitious attempt to overhaul the social security system in decades.
He has stood on his record in keeping Germany out of the Iraq war, appealed to Germans' deep attachment to the principle of solidarity and social balance and attacked the conservatives as cold, unsocial friends to the rich.
Merkel has accused him of botching his own reforms and lacking ideas for the future, contrasting Germany with more prosperous regions like Scandinavia.
She has pledged to raise value-added-tax and cut payroll 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.
Schroeder's reforms were bitterly resented, contributing to a string of election defeats that raise questions about how much pain any party will be able or willing to impose.
They also helped foster the rise of a new leftist party of former communists and disaffected ex-Social Democrats that has shaken German politics and looks on course to form the third largest party in parliament.
Spearheaded by former SPD leader Oskar Lafontaine, a bitter rival of Schroeder's, the Left Party has been attacked by all the other main parties as a pointless vehicle for protest votes.
But it is the party's strong showing, fuelled by anger over the costs that reforms have imposed on the poor and unemployed, that has upset the balance of power and may deny Merkel the majority she seeks.
(Additional reporting by Alexandra Hudson, Valdis Wish and Iain Rogers)