A joint Roman Catholic and Anglican document on Mary, the mother of Jesus, to be launched in London tomorrow, has been hailed as "a huge step forward" in relations between the world's two largest Christian denominations.
The Rev Dr Vincent Twomey, professor of moral theology at St Patrick's College, Maynooth, said it was "very significant" and "could only have happened with the approval of Pope Benedict".
The Pope spoke of the centrality to his mission of moves towards Christian unity, in his first address on April 20th.
Mary: Grace and Hope in Christ has also been welcomed, in holding statements - pending its publication at Westminster Abbey in London tomorrow - by both the Roman Catholic and Church of Ireland (Anglican) Archbishops of Dublin.
It has found common ground between Anglicans and Roman Catholics on the scriptural basis for the Catholic doctrines of the Immaculate Conception - that Mary was conceived without original sin - and the Assumption of Mary into Heaven.
It also stresses that Marian devotion and the invocation of Mary are not in any way to obscure or diminish the unique mediation of Christ.
However, differences remain over the authority with which the doctrines were proclaimed, both by popes rather than Church synods or such. Pope Pius IX proclaimed the doctrine of the Immaculate Conception in 1854 while Pope Pius XII proclaimed that of the Assumption in 1950.
The Roman Catholic Archbishop of Dublin, Dr Diarmuid Martin, said the document on Mary represented "the first major agreed statement by a formal international dialogue between two Christian world communions on this important aspect of Christian faith and devotion.
"The publication of the document marks another important and welcome step in the ongoing ecumenical dialogue between Anglicans and Roman Catholics."
The Church of Ireland Archbishop of Dublin, Most Rev Dr John Neill, said he had received a copy of the document and was "carefully studying" it.
"At present I can say that I welcome its publication and consider it an important development in the continuing ecumenical dialogue between Anglicans and Roman Catholics. It deserves and requires careful and prayerful consideration."
He will be publishing a personal response to it tomorrow.
Mary: Grace and Hope in Christ, also known as the Seattle Statement, where it was published on Monday, is the work of Arcic, the Anglican-Roman Catholic International Commission, which is the official instrument of theological dialogue between the Catholic Church and the churches of the Anglican Communion.
Prof Twomey attributed the commission's latest work to an initiative of the leader of the Anglican Communion, the Archbishop of Canterbury, Dr Rowan Williams, in his efforts "to stress what unites us rather than what divides".