States must be secular, according to Pope Francis, and "Confessional states end badly."

Speaking to French journal La Croix and responding to a question about "laïcité", the French system of the separation of Church and state, Francis said: "I believe that a version of laïcité accompanied by a solid law guaranteeing religious freedom offers a framework for going forward. "

He added: "If a Muslim woman wishes to wear a veil, she must be able to do so. Similarly, if a Catholic wishes to wear a cross. People must be free to profess their faith at the heart of their own culture, not merely at its margins."

France imposed a ban on Muslim women wearing a burqa to veil their faces in public in 2010. The ban was upheld by the European Court of Human Rights in 2014.

A move by Marks and Spencer to introduce "burkini" swimsuits was criticised by France's women's rights minister, Laurence Rossignol, who said: "What's at stake is social control over women's bodies. When brands invest in this Islamic garment market, they are shirking their responsibilities and are promoting women's bodies being locked up."

Pope Francis said in his La Croix interview: "The modest critique that I would address to France in this regard is that it exaggerates laïcité. This arises from a way of considering religions as sub-cultures rather than as fully-fledged cultures in their own right.

"I fear that this approach, which is understandable as part of the heritage of the Enlightenment, continues to exist. France needs to take a step forward on this issue in order to accept that openness to transcendence is a right for everyone."

Asked what he thought of France, the Pope said: "It is the eldest daughter of the Church, but not the most faithful!" He said he was fascinated by: "On one hand, that exaggerated laïcité, the heritage of the French Revolution, and on the other hand, so many great saints."