The leader of Roman Catholics in England and Wales has called for the National Gallery to surrender a Renaissance masterpiece – because it is a “work of faith” rather than art.

The Archbishop of Westminster, Cardinal Cormac Murphy-O’Connor, says that The Baptism of Christ, painted in the 1450s by Piero della Francesca, should be displayed in a religious setting such as Westminster Cathedral.

In a lecture as part of the Royal Fine Art Commission Trust’s Roots of Faith lecture series supported by Sky Arts, at Emmanuel College, Cambridge, the Cardinal said: “I would like to see this painting taken down from the walls of the National Gallery and placed in a Catholic church in London because it is a mistake to treat it as a work of art: it is a work of faith and piety, an expression of the Church’s life and a way into prayer.”

Earlier he told The Times: “Not only is it a beautiful aesthetic image but it also expresses the mystery of the Trinity and Christ revealed.” Such religious paintings should be made available for their original purpose in their original context, he suggested.

The Baptism of Christ, which hangs in the Sainsbury Wing, has been in the gallery’s collection since 1861, when it was bought from the Camaldolese Abbey at Borgo San Sepolcro, Piero’s native town. It was probably painted as part of an altarpiece in a chapel dedicated to John the Baptist.

It is painted on poplar and is so delicate that it is never lent out and is kept in controlled conditions. During the Blitz it was among the masterpieces sent to a colliery in Wales for protection. The work is beyond price: ensuring its security at the cathedral would be a huge undertaking.

The National Gallery said that visitors were welcome to pray in front of the painting where it was now.

Luke Syson, the gallery’s curator of Italian paintings of the period, said: “The National Gallery is a place for the contemplation of great art and of the subjects that great art treats.”

It was a place for appreciating paintings on many different levels, he said. “For some, Piero’s Baptism is a masterly artistic exercise in perspective and mathematical composition. For others, these aspects are intimately linked with Piero’s ability to set the protagonists of the Christian story into a rigorously, even miraculously, described universe.

“By seeing the picture in an especially secluded room which evokes a chapel setting, visitors can experience this masterpiece in any number of ways.”

Lord St John of Fawsley, a former Arts Minister, who today is chairman of the Royal Fine Art Commission Trust and also of Sky Arts, said of the Cardinal’s words: “I think it is a brilliant theological insight.” But he questioned who would foot the bill.

The other lecturers were the theologian Professor Hans Küng and the Chief Rabbi Sir Jonathan Sacks.

Sky Arts 2 will broadcast the lectures in the second week of December.