Istanbul (AFP)

Turkey's highest court rules on the reconversion of the former Hagia Sophia in a mosque on Thursday, a decision that President Recep Tayyip Erdogan calls for at the risk of creating tension with several countries.

A major architectural work built in the 6th century by the Byzantines who crowned their emperors there, Hagia Sophia is a UNESCO World Heritage Site and one of the main tourist attractions in Istanbul.

Converted into a mosque after the capture of Constantinople by the Ottomans in 1453, it was transformed into a museum in 1935 by the leader of the young Turkish Republic, Mustafa Kemal, anxious to "offer it to humanity".

Thursday, the Council of State studies the request of several associations requesting a return to mosque status. A decision could be made the same day, and at the latest within 15 days, according to the state press agency Anadolu.

As a sign that the case is worrying abroad, the United States on Wednesday called on Turkey not to touch the status of Hagia Sophia.

But Mr. Erdogan, a nostalgic for the Ottoman Empire who is today seeking to rally the conservative electorate amid an economic crisis due to the pandemic of new coronavirus, has several times said for a reconversion into a mosque.

Last year, he called the transformation of Hagia Sophia into a museum "a very big mistake".

- "Powerful symbol" -

Since the arrival of Mr. Erdogan in power in 2003, activities related to Islam have multiplied inside of Hagia Sophia, with notably sessions of reading the Koran or collective prayers on the square in front of the monument.

Mahmut Karagöz, a 55-year-old shoemaker, dreams of one day being able to pray under the dome of Hagia Sophia.

"It is a heritage from our Ottoman ancestors. I hope our prayers will be heard, this nostalgia must end," he told AFP.

For Anthony Skinner, of the consulting firm Verisk Maplecroft, converting Hagia Sophia into a mosque would allow Mr. Erdogan to satisfy his electoral base, to irritate Athens, with whom relations are strained, and to reconnect with the Ottoman past.

"Erdogan could not find a symbol as powerful as Hagia Sophia to achieve all of these goals at once," he said.

Last year, the Council of State had already authorized the reconversion into mosque of the superb Byzantine church of Chora in Istanbul, a decision perceived by some as a test balloon before Hagia Sophia.

The decision of the State Council on Thursday "will probably be political (...), the result of deliberations within the government," said Asli Aydintasbas, researcher at the European Council on Foreign Relations.

- Risk of tension -

For Aydintasbas, the government must weigh the pros and cons, especially through the prism of relations with Greece, Europe and the American administration of Donald Trump for whom "religion is an important subject".

In fact, the decision to convert a place as emblematic in the history of Christianity as the ancient Byzantine basilica into a mosque could cause tensions.

"We urge the Turkish authorities to continue to conserve Hagia Sophia as a museum, as an illustration of their commitment to respect the cultural traditions and the rich history which have shaped the Turkish Republic, and to ensure that it remains open to all "Secretary of State Mike Pompeo said on Wednesday.

The fate of Hagia Sophia is also of particular concern to neighboring Greece, which is closely monitoring the future of Byzantine heritage in Turkey.

In Turkey, too, there are many who oppose such a decision.

"Millions of tourists visit it every year," said Sena Yildiz, an economics student. "It is an important place for Muslims, but also for Christians and for all those who love history".

© 2020 AFP