Paris, France, Sep 17, 2011 / 12:25 pm (CNA/EWTN News).- New research suggests there are now more practising Muslims in France than practising Catholics.

While 64 percent of French people describe themselves as Roman Catholic, only 2.9 percent of the population actually practice the Catholic faith. That compares to 3.8 percent of the population who practice the Muslim faith. The research was carried out by the French Institute of Public Opinion on behalf of the Catholic newspaper La Croix.

More worrying for Islamic authorities in France is the finding that only 41 percent of the country’s 6 million Muslims actually describe themselves as “practising,” although 75 percent are happy to label themselves “believers.” Seventy-percent also claim to observe the Islamic holy month of Ramadan.

Most French Muslims hail from the country’s former colonies in North and sub-Saharan Africa.

There is also further evidence that mosques are being erected at a much faster rate than Catholic churches. Mohammed Moussaoui, President of the Muslim Council of France, last month estimated that 150 new mosques are currently under construction across the country.

By contrast, the Catholic Church in France has built only 20 new churches during the past decade, and has formally closed more than 60 churches. Many of these are now destined to become mosques, according to La Croix.

Research in 2009 by the Amsterdam School for Social Science Research suggested that nearly 500 new mosques were built between 2001 and 2006, taking the present total to over 2,000. Many of these new buildings, however, were erected to re-accommodate local Islamic communities who had previously been using temporary accommodation – the so-called “Islam of the basements.”

One of France’s most prominent Muslim leaders, Dalil Boubakeur, who is the head of the Grand Mosque of Paris, recently called for the number of mosques in the country to be doubled again – to 4,000 – to meet growing demand.

The lack of building space for France’s Islamic population had led to many mosques not being able to accommodate the believers who arrive for Friday prayers, leaving many Muslims to pray outside in the streets.

But Muslims praying outside of mosques has created political tension.

In December 2010 the leader of the far-right National Front, Marine Le Pen, described such scenes as an “occupation without tanks or soldiers.” She is likely to run for the French presidency next year, and her message is resonating with 40 percent of voters, according to a recent poll for the “France Soir” newspaper.

French President Nikolas Sarkozy has also recently described street prayers as “unacceptable,” adding that the street cannot become “an extension of the mosque.” Last month his Interior Minister, Claude Guéant, suggested Muslims should instead use empty barracks. Prayer in the street “has to stop,” Guéant declared.

In a bid to solve the space crisis in the southern city of Marseille, a mosque to accommodate 7,000 worshippers is currently being built. Twenty-five percent of Marseille's population is Muslim.

Last month a mosque for 2,000 worshippers opened in the eastern town of Strasbourg, where 15 percent of the population is Muslim.

France is often referred to as the “eldest daughter of the Catholic Church,” because the local Church has maintained unbroken communion with the Bishop of Rome since the 2nd century.

But some senior European bishops have long predicted the eclipse of Catholicism by Islam across the continent.

In 1999, Archbishop Giuseppe Bernardini, an Italian Franciscan who heads the Izmir Archdiocese in Turkey, recalled a conversation he had with a Muslim leader for the Synod of European Bishops, which was gathered in Rome. That leader told him, “thanks to your democratic laws, we will invade you. Thanks to our religious laws, we will dominate you.”