"CDU wants Muslim holiday. This is the difference: AfD says NO! NO! NO!" — Beatrix von Storch, Deputy Chair of the Alternative for Germany party (AfD).

"We have a Judeo-Christian religious character, not an Islamic one. Therefore, I do not understand why we are even having this debate. Instead, we should discuss something else: When will Christians in all Islamic countries have the same religious freedom as Muslims have here?" — Wolfgang Bosbach, a senior member of the CDU party.

"Germany's Christian heritage is not negotiable. The introduction of Muslim holidays is out of the question for us." — Alexander Dobrindt, a senior member of the CSU party.

An off-the-cuff proposal by German Interior Minister Thomas de Maizière to introduce Muslim public holidays has sparked another furious debate over the role of Islam in Germany.

Speaking at a campaign rally on October 9 for state elections in Lower Saxony, de Maizière, a member of Chancellor Angela Merkel's Christian Democratic Union (CDU), said that federal states with large Muslim populations should be allowed to celebrate Muslim public holidays:

"I am prepared to discuss the possibility of introducing Islamic holidays. In areas where a lot of Catholics live, we celebrate All Saint's Day, and in areas where not a lot of Catholics live we don't celebrate All Saint's Day. So why can't we think about Islamic holidays as well?"

A proposal by German Interior Minister Thomas de Maizière to introduce Muslim public holidays has sparked another furious debate over the role of Islam in Germany. Pictured: De Maizière (right) with Sheikh Ahmad Al-Tayeb, the Grand Imam of Cairo's s Al Azhar mosque, on May 26, 2017 in Berlin, Germany. (Photo by Steffi Loos/Getty Images)

De Maizière's statement, apparently aimed at enticing Muslim voters, prompted a furious backlash from his own party and political allies, who are still reeling from the CDU's poor results in the general election on September 24. Although Merkel won a fourth term in office, the CDU, together with its Bavarian sister party, the Christian Social Union (CSU), suffered its worst electoral result in more than half a century.

Party insiders blame the election debacle on Merkel, who they say has moved the CDU too far away from its conservative roots, especially on immigration. More than a million traditional CDU/CSU voters defected to the anti-immigration Alternative for Germany (AfD), an upstart party that harnessed widespread anger over Merkel's decision to allow into the country more than a million mostly Muslim migrants from Africa, Asia and the Middle East.

Germany's Muslim population surpassed six million in 2016 for the first time ever. Germany now vies with France for the highest Muslim population in Western Europe.

The increase in Germany's Muslim population is being fueled by mass migration. An estimated 300,000 migrants arrived in Germany in 2016, in addition to the more than one million who arrived in 2015. At least 80% (or 800,000 in 2015 and 240,000 in 2016) of the newcomers were Muslim, according to the Central Council of Muslims in Germany.

In addition to the newcomers, the rate of population increase of the Muslim community already living in Germany is around 1.6% per year (or 77,000), according to data extrapolated from a Pew Research Center study on the growth of the Muslim population in Europe.

Based on Pew projections before the current migration crisis, the Muslim population of Germany was to have reached an estimated 5,145,000 by the end of 2015.

Adding the 800,000 Muslim migrants who arrived in Germany in 2015, and the 240,000 who arrived in 2016, combined with the 77,000 natural increase, the Muslim population of Germany jumped by 1,117,000, to reach an estimated 6,262,000 by the end of 2016. This amounts to approximately 7.5% of Germany's overall population of 82 million.

"Germany's Christian heritage is not negotiable," said Alexander Dobrindt, a senior member of the CSU. "The introduction of Muslim holidays is out of the question for us."

Another CSU member, Stephan Mayer, added, "Germany has for centuries been shaped and defined by the Christian tradition. Nothing has changed to this day. The notion that Islam belongs to Germany cannot anywhere be proven in our past or present history."

CSU vice-chairman, Manfred Weber, said: "Holidays above all represent the religious character of a country, not for individual population groups. Germany undoubtedly has a Christian character."

Senior CDU member Wolfgang Bosbach said: "We have a Judeo-Christian religious character, not an Islamic one. Therefore, I do not understand why we are even having this debate. Instead, we should discuss something else: When will Christians in all Islamic countries have the same religious freedom as Muslims have here?"

Deputy Chair of the Alternative for Germany (AfD), Beatrix von Storch, tweeted: "CDU wants Muslim holiday. This is the difference: AfD says NO! NO! NO!"

The Central Committee of German Catholics (ZdK), by contrast, expressed openness to the idea of introducing Muslim holidays: "In a multi-religious society, an Islamic holiday can be added in areas with a high percentage of religious Muslims without the Christian tradition of our country being betrayed."

CSU Secretary General Andreas Scheuer responded: "I am deeply dismayed, even bewildered, that the Central Committee of Catholics is now also calling for an Islamic holiday."

Aiman Mazyek, the head of the Central Council of Muslims in Germany, said that introduction of Muslim public holidays would foster integration. Such holidays would show that Muslims are a part of Germany and would be "a sign of mutual understanding as well as good and friendly coexistence."

The leader of the Social Democratic Party (SPD), Martin Schulz, criticized the CDU and CSU for attacking de Maizière: "We should think about this proposal."

Cem Özdemir, the German-Turkish head of the Greens, said that ​​introducing a Muslim holiday was unnecessary. "I see no need for action. Muslims today are already free to celebrate. The CDU and the CSU should deal with the important issues, above all with excellent education for all. This could strengthen social cohesion."

The German constitution establishes that all 16 federal states can decide on their own which religious public holidays are celebrated; the central government actually does not have a say on the issue. In 2012, for example, Hamburg and Bremen concluded wide-ranging agreements with their Muslim communities to establish Muslim holidays there.

De Maizière has since backtracked. In a statement issued on October 17, he said that in his opinion, German society was founded on Christian roots and will continue to be so: "That was the starting point. On this foundation, I took up an idea to discuss a Muslim holiday in regions with a very high proportion of Muslims. There is no suggestion of introducing a Muslim holiday. Nor will I will make such a proposal."