(Bloomberg) -- On an industrial estate in the French city of Strasbourg a few miles from the European Parliament, a grand plan to build the continent’s largest mosque is slowly taking shape.

The Turkish organization behind the 30 million-euro ($36 million) project says the Eyyub Sultan complex, replete with a dozen domes and minarets and surrounded by conference halls, restaurants and stores, will be open to all and a pillar of integration and multiculturalism. Yet what’s concerning French authorities is how it might ultimately be used.

With France reeling from a series of gruesome attacks by jihadists in recent weeks, President Emmanuel Macron has spoken of “a battle” to protect the country’s secularism. Critical to that, he says, is to halt the import of more conservative interpretations of Islam. Top of his list is Turkey as it vies for leadership of the Sunni Muslim world with Saudi Arabia.

Turkish President Recep Tayyip Erdogan sees the diaspora as an army in Europe keeping strong links with the country, said Gilles Kepel, a French political scientist specializing in Islam in the West and who has close ties to Macron. “The propaganda machine of Turkish nationalism is very strong,” said Kepel. “Erdogan has been building a network to relay his influence.”

The nascent mosque in eastern France—currently a beige shell with a crescent of arched windows—is the most prominent example of Turkey’s growing footprint in the country as Macron and Erdogan engage in a toxic row over the role of Islam.

Macron is due to hold talks with Austrian Chancellor Sebastian Kurz and Germany’s Angela Merkel on Tuesday following last week’s attacks in Vienna by what the authorities there called an “Islamist terrorist.” Topics include the fight against indoctrination by religious extremists, according to a draft of the agenda. European Union leaders are then set to discuss a coordinated crackdown on radicalization.

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Erdogan last month said his French counterpart needed mental checks and called for a boycott of French goods after Macron described Islam as a religion “in crisis.”

After France moved to ban the nationalist group Grey Wolves, Ankara vowed to respond “in the strongest possible way,” yet it also denied its existence and accused the French government of ignoring “the incitement, threats and attacks” against Turks in France. Days later, France hinted at possible new sanctions against Turkey over what it called “declarations of violence.”

Erdogan says that he seeks only to look out for Muslims living in Europe, where he says Islamophobia and racism are rampant. He also has his own problems at home, firing the central bank governor at the weekend after a run on the currency.

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But the French government is right to monitor Turkey’s influence, said Elise Massicard, a Paris-based researcher at the Paris Institute of Political Studies, or Sciences Po. The authorities are also concerned that Turkish classes funded by Turkey allow Erdogan to spread influence.

“Turkey has been seeking to deploy Turkish Islam in Europe,” she said. “There’s this idea that members of the Turkish diaspora should speak the language and practice the religion like in Turkey. The country is reluctant to see members of the diaspora distancing themselves from their culture and being molded by the French system.”

The risks were clear at the end of October when men draped in Turkish flags marched in the streets of Lyon amid tension between Armenian and Turkish communities over the conflict in Nagorno-Karabakh.

A memorial center devoted to the 1915 mass murder of Armenians by the Ottoman Empire was defaced with yellow graffiti that included Erdogan’s initials and the words “Loup Gris,” or “Grey Wolf.” Unrest spread to the city of Dijon.

Tension between France and Turkey is playing out in many theaters, including the conflicts in Syria and Libya. Over the summer, the French leader spearheaded criticism of Turkish energy exploration in contested waters in the eastern Mediterranean, promising to send warships to support Greece. 

It’s Turkey’s soft power, though, that is becoming a more pressing government concern as Macron tries to avoid far-right nationalist Marine Le Pen gaining political traction from the issue before elections in 2022.

The resurgence of jihadist violence and cases of Covid-19 now hitting daily records have clearly rattled the French leader, according to a person familiar with the discussion between Macron and EU leaders at a virtual summit last month.

The primary driver of Turkey’s outreach is Diyanet, or Religious Affairs Directorate, which Erdogan has expanded significantly since his AK Party took power in 2002. It pays the salaries of about 150 of the Turkish imams in France, or half of the total number of foreign imams in the country, according to the French government.

“We are the guides, the leaders,” Diyanet chief Ali Erbas said in a speech in Strasbourg in January 2019. “We need to train our Muslim brothers in such a way as to maintain their Islamic sensibilities. We need to raise children, youth, with our sermons, our training.”

Indeed, the influence is strongest in the eastern French region of Alsace, where Strasbourg is the main city. It’s adjacent to Germany, where Turkey’s use of Islam as a glue to keep millions of its citizens together in Europe is most prominent.

The land on which the Eyyub Sultan mosque is being built was purchased by the Islamic Community of Milli Gorus. The project is funded by believers, members from across Europe and also by Christians, according to its imam, Eyup Sahin, the local leader of Milli Gorus.

To the north lies a new Turkish consulate building, and to the west sits a branch of Ditib, the Germany-based arm of the Diyanet. It manages 270 mosques in France.

Ditib was set up in the 1980s to serve Turkish immigrants when Ankara still championed secularism, while Milli Gorus traces its roots back to the 1960s to foster the political Islam that Erdogan now supports. Both now represent a conservative interpretation of Islam, and have been seeking to cater to all Muslims, not just the Turkish community, said Massicard at Sciences Po.

For years, France has regarded the two organizations as key partners on matters of faith and integration. Events more recently led the authorities to monitor activities, according to people familiar with the situation.

Sahin said Milli Gorus has no ties to Erdogan or his AK Party. He said he’s in touch with local intelligence officers and has spoken out against violence and threats in the name of Islam. Sahin manages a training center for imams and said it’s important preachers understand French culture and are able to speak the language.

“It’s ignorant to say that Strasbourg is Erdogan’s entry point in Europe—frankly it makes us laugh,” said Sahin, who is also the local head of CFCM, an organization created by the state for dialog with representatives of Islam. “Alsace is a model of co-existence of religions with a very good relationship between the state, the city and faiths.”

In an Oct. 2 speech on uniting the country under its secular values, Macron said he planned more control over imams and vowed to shut down mosques and organizations deemed a threat. But in Strasbourg, former and current city officials say there isn’t much that can be done to prevent the expansion of Turkey’s influence and the community can’t be denied space to worship.

For now, it’s not certain Milli Gorus will be able to raise enough money to finish the new mosque, or even if it will end up being as large as the one in Cologne that’s managed by Ditib and was opened by Erdogan in 2018.

“The issue isn’t religion,” said Roland Ries, the former mayor of Strasbourg whose administration approved the mosque plan in 2014. “The issue is the use of religion to achieve political or territorial domination.”

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