Nearly four years after a rare outburst of national pride over the election of a German pope, Germans are falling out of love with Pope Benedict because of his rehabilitation of a bishop who denies the Holocaust.

Prominent Catholics, politicians and newspaper commentators in Joseph Ratzinger's homeland are pulling no punches in their criticism of his lifting of the excommunications of four bishops, including one who denies the extent of the Holocaust.

In a rare move, even Chancellor Angela Merkel criticized him, saying that the Vatican must make clear that it does not tolerate any denial of the Holocaust.

"I do not believe that sufficient clarification has been made," Merkel said.

"Worldwide criticism of the Pope," read the front page of top-selling German daily Bild which devoted most of its second page to the furore. It was a stark contrast to the jubilant "We are the pope!" headline in April 2005 to celebrate his election.

"The pope has made a serious mistake. That he is a German pope makes the matter especially bad," read its editorial.

"Pope Benedict XVI is inflicting great damage on Germany... The pope must correct his mistake, reverse his decision and excuse himself," it said, in comments echoed by other papers.

Former foreign minister Hans-Dietrich Genscher wrote in the Mitteldeutsche Zeitung: "Poles can be proud of Pope John Paul II. At the last papal election, we said "We are the pope!" But please -- not like this."

The Vatican on Tuesday moved quickly to counter any suggestion that the pope has been unclear in his stance on the Holocaust. "The pope's thinking on the subject of the Holocaust has been expressed very clearly," said Vatican spokesman Rev. Federico Lombardi.

He cited Benedict's visit to a synagogue during his first visit to Germany as pope in 2005, a visit to Auschwitz in 2006 and his remarks during last week's general audience.

Lombardi quoted from what he called the pope's unequivocal words at that public audience. "I hope that the memory of the Shoah leads humanity to reflect on the unpredictable power of evil when it conquers the heart of men," he quoted the pope as saying. "May the Shoah be a warning for all against oblivion, against denial or reductionism."

Lombardi said that during the audience the pope himself clearly explained the purpose of lifting the excommunication, which has nothing to do with any legitimization of positions denying the Holocaust, which were clearly condemned by Benedict.

More than 60 years after the end of World War Two, Germans are still struggling to come to terms with the legacy of the Holocaust, in which Nazis deliberately killed 6 million European Jews, and relations with the Jewish community are highly charged.

Last week, Germany's Central Council of Jews said it was breaking off ties with the Catholic Church over the pope's move.

The rehabilitated bishop at the centre of the storm is Richard Williamson, who belongs to the ultra-traditional Society of Saint Pius X and denies the extent of the Holocaust.

Last month, the British-born bishop told a Swedish broadcaster he believed there were no gas chambers and no more than 300,000 Jews perished in concentration camps.

Holocaust denial is a crime in Germany and state prosecutors in the southern city of Regensburg are investigating Williamson for incitement. German neo-Nazi websites and blogs have published contributions supporting Williamson's stand.

In his commentary, Genscher argued that Ratzinger, forced to join the Hitler Youth as a boy though his parents opposed the Nazis, was making a habit of offending non-Catholics.

He has shown little respect to Protestants and angered Muslims by hinting Islam was violent and irrational in a 2006 speech in Regensburg, Genscher said.

"This is a deep moral and political question. It is about respect for the victims of crimes against humanity," he wrote.

Other politicians joined in and in an unusual intervention Chancellor Merkel, daughter of a Protestant pastor, called on him to make clear he rejected any Holocaust denial.

"It is a fundamental question if, through a decision by the Vatican, the impression arises that the Holocaust can be denied," she said, adding she wanted the pope to issue a clarification.

The pope has also faced harsh criticism from German Catholics. Hamburg Archbishop Werner Thissen was quoted as saying the decision risked undermining trust in the church.

Cardinal Karl Lehmann, former chair of Germany's Catholic bishops' conference and head of Germany's 26 million Catholics, has described the affair as a catastrophe. Others say it has exposed flaws in the pope's detached governing style.

"It's an unforgivable mistake, and also a political error that Swiss, German and French bishops' conferences, where most people of the brotherhood live, were not informed beforehand," widely respected theologian Hans Maier told Vatican Radio.