In a provocative speech at the Gregorian University in Rome last night, Dr Rowan Williams said the historic Catholic prohibition against women in holy orders had become a "clear obstacle" to unity with Anglicans.
He acknowledged, however, that for some Anglicans not ordaining women had "a possible unwelcome implication about the different between baptised men and baptised women".
He challenged the Roman Catholic Church to consider how much filial and communal holiness were undermined by ordaining women ministers.
"In what way does the prohibition against ordaining women so 'enhance the life of communion', reinforcing the essential character of filial and communal holiness as set out in Scripture and tradition and ecumenical agreement, that its breach would compromise the purposes of the Church as so defined?" he said.
Anglican provinces that ordain women had, he maintained, "not become so obviously diverse in their understanding of filial holiness and sacramental transformation that they cannot act together, serve one another and allow some real collaboration".
"I am asking how far continuing disunion and non-recognition are justified, theologically justified in the context of the overall ecclesial vision, when there are signs that some degree of diversity in practice need not, after all, prescribe an indefinite separation," he said.
Dr Williams delivered his speech as part of celebrations marking the centenary of Cardinal Willebrands, former president of the Pontifical Council for Promoting Christian Unity.
He is in Rome for his first visit to the Vatican since the announcement of a new structure to incorporate Anglicans upset over the ordination of women priests and, in the Church of England, the prospect of women bishops. The Archbishop is expected to discuss the implications of the Apostolic Constitution with the Pope when they meet today.