BERLIN (Reuters) - German politicians on Sunday condemned as "unacceptable" and "absurd" comments by former Italian Prime Minister Silvio Berlusconi that Germans denied the existence of Nazi concentration camps.

Social Democrat (SPD) General Secretary Yasmin Fahimi described the comments as "repugnant, shocking and completely unacceptable".

"These lapses ... not only damage the image of Italy but also endanger the political culture and values of Europe," she told Reuters.

She demanded that conservative Chancellor Angela Merkel respond. Merkel's Christian Democrats (CDU) are allies of Berlusconi's Forza Italia in the European parliament's European Peoples Party conservative grouping.

CDU General-Secretary Peter Tauber said the comments were "so absurd that they don't deserve commenting on".

Berlusconi said on Saturday: "According to the Germans, there never were concentration camps."

He caused a storm in 2003 by jokingly offering German Social Democrat Martin Schulz a film part as a concentration camp "kapo", or inmate appointed as an overseer.

Social Democrat Schulz told Der Spiegel magazine on Sunday it was also shocking that an Italian sister party of the CDU was campaigning for May's European elections with anti-German slogans, such as "More Italy, Less Germany".

"Such a slogan is outrageous," he said.

German conservative Herbert Reul also criticized the slogan, saying it was "out of order" and he could not understand it.

Anti-German rhetoric has been on the rise in Italy and other heavily indebted euro states, since the euro zone crisis led to German demands for economic austerity.

(Reporting by Madeline Chambers and Holger Hansen; editing by Andrew Roche)