Muslims in Spain are campaigning to be allowed to worship alongside Christians in Cordoba Cathedral — formerly the Great Mosque of Cordoba.

Today, at the original Cordoba mosque in Spain, there is no call to prayer, only the ringing of church bells. That’s because the former mosque is now a working Catholic cathedral, performing a daily mass.

It’s been a Cathedral since Spain’s Christian monarchy conquered Cordoba in the 13th century, but the site remains significant for Muslims as a symbol of Islam’s golden age of learning and religious tolerance. The Mosque of Cordoba was once famed for allowing both Christians and Muslims to pray together under the same roof.

Now, some Muslims are trying to repeat that history. Mansur Escudero, a Spanish convert to Islam, is leading the movement that is pushing for the right of Muslims to pray at the Cordoba Cathedral.

“I don’t think it’s important for Muslims. I think it’s important for humankind,” Escudero says. “We think this is a beautiful paradigm of tolerance, knowledge, culture. People of different religions living together.”

See also: Do Muslims, Jews and Christians worship the same God?

The proportion of Spaniards who say they are Roman Catholic has fallen to 73 percent from around 80 percent eight years ago, according to a survey released Thursday by the CIS research centre.

About 25 percent of all Spaniards now claim to be atheists or without a religion, compared to 17 percent in 2002, the June survey of 2,500 adults found.

Five people were arrested in a dawn raid yesterday on a chalet on the outskirts of Llíber (Alicante) including the leader of an alleged 'religious sect'. A Denia judge has ordered that the details of the case should be kept secret.