By Madeline Chambers

BERLIN (Reuters) - Angela Merkel is seeking help from her estranged, former mentor Helmut Kohl, architect of the euro, to restore voter faith in the European project before next year's election.

Realizing her own future is tied to that of the EU, Merkel has in the last month softened her rhetoric towards the most indebted euro zone states. Next week she will make a rare joint appearance with former Christian Democrat (CDU) chancellor Kohl.

The German leader's tough approach to the euro debt crisis has boosted her popularity in the last two years and polls show she is in a strong position to win the September 2013 vote.

But she needs to ensure traditional conservatives in her own party maintain discipline in the run-up to the vote after some were angered by her defense of European Central Bank President Mario Draghi's bond-buying plan for stricken euro states - a scheme the German Bundesbank opposes.

Merkel must also convince the broader electorate of the need for closer EU integration, seen as crucial to the currency's long-term survival. A poll this week showed almost two thirds of Germans would prefer to live without the euro and 49 percent without the EU.

Getting the 82-year-old Kohl, Germany's longest serving chancellor, on board is something of a coup for Merkel.

The statesman is known to bear a grudge against Merkel for turning on him in 1999 over a party funding scandal that tainted his image, and has voiced veiled criticism of her handling of the crisis.

"A reconciliation with Kohl has important symbolic value, he still commands wide respect especially on the issue of Europe," said Klaus-Peter Schoeppner, head of the Emnid polling group.

Schoeppner sees the joint appearance, to mark 30 years since Kohl became chancellor, as part of a shift in Merkel's strategy to broaden her message and sell the benefits of Europe.

Kohl, frail and wheelchair-bound, is seen as the architect of German reunification and was a driving force, along with French President Francois Mitterrand, behind the creation of the euro.

He plucked Merkel out of obscurity in the former communist East after the fall of the Berlin Wall and she quickly became a protegee. Kohl brought her into the first post-reunification cabinet, referring to her as his "Maedchen", or girl.

But Kohl, who grew up in World War Two and religiously stresses that the euro holds the key to ensuring lasting peace in Europe, has been unimpressed with her crisis management.

Last year he criticized Merkel's foreign and European policy, saying it lacked direction and that she was making Germany an undependable partner. According to Der Spiegel weekly, Kohl complained to a friend: "She is destroying my Europe" although he has since denied saying that.

Not least to protect his euro legacy, Kohl will let bygones be bygones on September 27 and sit alongside Merkel at Berlin's Historical Museum with former European Commission President Jacques Delors to hear speeches honoring him.

Other events include a visit to conservatives in parliament by Kohl, who rarely leaves his home in the small western town of Oggersheim, and festivities in the former capital of Bonn.

"Kohl is supposed to help Merkel keep the CDU on a pro-European path. He stands for a Europe that is not dominated by an incomprehensible alphabet-soup of EFSFs and ESMs. For the chancellor, Kohl is a welcome bulwark against euro populists such as individuals in (Bavaria's) Christian Social Union," (CSU) wrote Der Spiegel.

SOFT TOUCH

Scarred by guilt about World War Two, Germans have always been committed to the idea of the EU but many were reluctant to give up the deutsche Mark, a symbol of West Germany's post-war economic miracle, for the euro.

That the euro has fueled export-led growth in Europe's biggest economy is a point often lost on Germans, many of whom see themselves as victims of the euro debt crisis and resent the 310 billion euros in guarantees to the area's most indebted states.

For months, dissenters in Merkel's conservative ranks have voted against bailout funds in parliament. Some in the CSU have stepped up calls for Greece to leave the euro zone - a scenario Merkel is desperate to avoid before the election.

Merkel's swift rebuke to the most vocal critics of Greece is a sign of the more diplomatic approach she has adopted towards her EU partners since the summer break.

"Europe is in a decisive phase... we have to weigh our words very carefully," she said last month.

In meetings with Italy's Mario Monti and Greek Prime Minister Antonis Samaras. Merkel has shifted her emphasis, praising austerity measures she knows she could never force on German voters and avoiding the threats she made a year ago.

"She has eased off on the bashing of the southern European states," said Peter Matuschek of the Forsa polling group. "She has realized she can't overstretch these countries and has changed her rhetoric accordingly."

Merkel has also dispatched Foreign Minister Guido Westerwelle, a member of her Free Democrat (FDP) coalition partners, to promote the political and cultural values of Europe.

"Europe has a price but it also has its value," Westerwelle said in a speech on Tuesday, pointing to freedom, democracy and the protection of minority rights as pillars of the bloc.

He is leading the "Future of Europe Group" of 11 EU foreign ministers, who have drawn up proposals to set up a European Monetary Fund, strengthen the European parliament and give more clout to the European Commission.

To counter anti-euro sentiment in Germany, an "I want Europe" publicity campaign was launched last month in which prominent Germans, from footballer Philipp Lahm to Daimler chief Dieter Zetsche and former chancellor Helmut Kohl declare their commitment to the European project.

Initiated by the Mercator and Robert Bosch foundations, the television, print and online campaign has German President Joachim Gauck as its patron. Its aim is to influence the German debate on Europe, dominated until now by a media-driven narrative of lazy, spendthrift Greeks keen for German cash.

"There was an initial desire (in Europe) to punish Greece rather than help it," said Philip Whyte, senior research fellow at the London-based Centre for European Reform.

"Germany played a big role in that and the benefits of Germany's euro zone membership weren't highlighted much. This is starting to change... though it would have helped if this had happened sooner," he said.

(Reporting by Madeline Chambers; Editing by Noah Barkin and Janet McBride)