Pope Benedict will issue his findings on Luther (1483-1546) in September after discussing him at his annual seminar of 40 fellow theologians — known as the Ratzinger Schülerkreis — at Castelgandolfo, the papal summer residence. According to Vatican insiders the Pope will argue that Luther, who was excommunicated and condemned for heresy, was not a heretic.

Cardinal Walter Kasper, the head of the pontifical Council for Promoting Christian Unity, said the move would help to promote ecumenical dialogue between Catholics and Protestants. It is also designed to counteract the impact of July’s papal statement describing the Protestant and Orthodox faiths as defective and “not proper Churches”.