* Chancellor tipped for third term in Sunday election
* Merkel's centre-right coalition may not survive
* Small Eurosceptic party is wild card in election
Angela Merkel wrapped up her re-election campaign on Saturday with an appeal to defend Europe and her centre-right coalition against Eurosceptics who threaten to break into the German parliament for the first time in Sunday's election.
With a third of the 62 million voters still undecided and the small Alternative for Germany (AfD) tapping into impatience with euro zone bailouts, Europe's most powerful leader risks spending her third term in an awkward right-left coalition.
"Lots of people won't make up their mind until the last minute. Now is the time to reach every undecided voter and get their support," she told supporters in Berlin, before flying to her Baltic coast constituency for a final campaign stop.
She did not name the AfD, who have emerged in seven months to become the wild card of Germany's first federal election since the euro zone debt crisis began. The AfD wants Greece and other struggling states to be expelled from the single currency.
But Merkel spent half her speech defending the European Union, which had been largely ignored in the campaign because her Christian Democrats (CDU) and the main opposition Social Democrats (SPD) mostly agree on how to tackle the crisis.
"Europe is economically important, yes, but it is much more than that. Next year we'll be thinking back to the start of the World War One 100 years ago," said the 59-year-old chancellor. "Most of us here have never had to live through war."
"In the coming years we must keeping working for the success of this wonderful continent," she said to loud applause.
The AfD's rapid rise in the polls forced the CDU to change tactics at the last minute. After studiously ignoring it, they brought out respected Finance Minister Wolfgang Schaeuble this week to attack it as "dangerous" for Germany's economy.
Polls put Merkel's conservatives about 13 percentage points ahead of the SPD, meaning she will almost certainly become the third post-war chancellor to win a third term.
But her coalition with the struggling Free Democrats (FDP) and the combined leftist opposition are neck-and-neck in polls, making the vote in Europe's largest economy too close to call.
She could win a slim majority with the FDP or be forced into talks with the SPD that could drag on for months and result in changes to her cabinet, including the departure from the finance ministry of Schaeuble, who has been a key player in the crisis.
The AfD's surge to just under the 5-percent threshold for entering the Bundestag lower house risks depriving Merkel of her centre-right majority and stirs concern about Euroscepticism - though the party's impact on policy would be limited.
"Keep cool and vote for our chancellor!" and "Angie" read banners in the crowd of about 4,000 CDU supporters in a Berlin boxing arena just around the corner from SPD headquarters.
"Merkel is doing a great job leading the country and deserves another term," said Wolfgang Schwarz, a 54-year-old lawyer who voiced uncertainty about what kind of governing coalition would emerge after Sunday's election.
Theresa Neubauer, a 25-year-old entrepreneur, said Merkel's speech was "full of passion" on Europe. "I don't like the AfD and I hope they don't get into parliament on Sunday," she said.
But while Merkel has high popularity ratings, not everyone is convinced. Ingrid Gaukler, a 35-year-old actress, said she did not like Merkel and was "dragged" to the rally by a friend.
"I don't like her energy policies, I don't like the way the CDU gives preferential tax treatment to married couples and I want to see a minimum wage. Her policies are only designed to help the rich," she said. "But I'm here with an open mind."
Merkel's challenger Peer Steinbrueck has had a tough time convincing voters that his SPD can do a better job.
She is credited with leading Europe safely through the debt crisis and ensuring Germany economic growth and an unemployment rate that is near post-unification lows. Steinbrueck, who argues that Merkel has spread income inequality, wants higher taxes on the rich and a minimum wage of 8.50 euros an hour.
Steinbrueck was finance minister in Merkel's last 'grand coalition' with the SPD from 2005-2009, which cost his party millions of votes in 2009. It has since veered further left and would exact a high price for joining another Merkel government.
"In 28 hours you can get rid of them, you can get rid of the most backward-looking, least capable, most loud-mouthed German government since reunification," the SPD candidate told a final rally in Frankfurt, Germany's financial centre.
But he joined Merkel in defending the euro against critical voices like the AfD, whom he calls "rabble-rousers".
Steinbrueck, whose party could push German policy on the EU closer to the pro-growth and pro-integration stance of southern euro states and France, said a collapse of the euro and return of the deutsche mark would be ruinous for Germany and Europe.
"We are the first generation not be sacrificed on the slaughter fields," he said. "That is an exception in German history and means we have a clear responsibility to Europe."