Next year’s Amazon synod is coming into focus, after Pope Francis named an 18-person preparatory committee to help draw up the synod’s agenda.

The official theme is “Amazonia: new pathways for the Church and for an integral ecology”, and it will address the difficulties of a region troubled by poverty, environmental destruction and a lack of clergy to cover a vast area.

Several bishops and theologians in the Amazon region have proposed allowing married priests. While supporters of the move see it as a necessary practical response to a priest shortage, critics say it is a “backdoor” way to undermine clerical celibacy in the Church.

That debate is likely to heat up, as two of the committee members are prominent backers of married priests – and appear to be open to women’s ordination, an idea which the Church has decisively ruled out.

One committee member, Bishop Erwin Kräutler, former Bishop of Xingu in Brazil, spoke to Pope Francis in 2014 and 2015 about the possibility of ordaining married men.

His place on the committee is likely to mean that the proposals of Bishop Fritz Lobinger will be front and centre when the bishops meet in Rome eighteen months from now.

Bishop Lobinger, whom Bishop Kräutler has cited with approval, has pioneered the idea of “viri probati” – older men from the community who will be ordained to carry out a special ministry. On Bishop Lobinger’s view, they could be married, would not go to seminary, and would be “as distinct as possible” from priests.

If this sounds radical, that’s because it is. And its antecedents make it look even more so: the notion of “viri probati” has been a favourite concept of theologians who wish to rewrite the idea of priesthood.

Leonardo Boff, who claims to have helped Pope Francis to write Laudato Si’, has argued that the Church “simply may not…maintain its traditional prohibitions” on women priests. Interestingly, the “reconstitution” of the priesthood on a “viri probati”-style model is seen as the prelude to women priests: Boff has quoted with approval a fellow-theologian as saying, “Only when it has been transformed from within, and reconstituted in relation to the community as a whole, might it become something transferable to women.”

(Pope St John Paul II and Cardinal Joseph Ratzinger condemned some of Boff’s writings because they “endanger the sound doctrine of the faith”.)

It is noteworthy that Bishop Lobinger, pioneer of “viri probati”, has written that “Because the majority of proven local leaders are women, it is unavoidable that the question of their inclusion among ordained elders will arise, though present church law does not permit it.”

The reference to “present church law” might be said to understate the binding nature of Church teaching on this question.

Bishop Kräutler, who will be on the synod committee, appears to have similar views. He told Die Presse in 2014 that the door to women priests wasn’t permanently closed. And should it be opened? the newspaper asked. “Yes,” Bishop Kräutler replied.

Somewhat less controversial, but more prominent, is another committee member, Cardinal Claudio Hummes, a friend of Pope Francis who has more than once raised the possibility of married priests.

According to Boff, the cardinal made a special request for priests who, having left the priesthood, were now married, to be allowed to return to active ministry.

As for Cardinal Hummes’s other views on the priesthood: he said in 2014 that the Church might revisit women’s ordination. (Asked in the same interview whether Jesus Christ would back gay marriage, he said he didn’t know.)

Other members of the committee are closely involved with issues facing the people of the Amazon. Archbishop Roque Paloschi, president of the Brazilian bishops’ indigenous missionary council, has written of the “disastrous consequences” of “indifference, the advance of large agri-business projects, construction of large hydroelectric plants, mining and devastation of the environment in general”.

Another, Bishop Eugenio Coter, has opposed the Bolivian government’s legislation on land use, saying that it infringes the rights of indigenous people.

The synod committee also includes former collaborators of Pope Francis, such as Archbishop Pedro Jimeno and Cardinal Carlos Retes, who worked with the Pope on the Aparecida statement, issued by Latin American bishops in 2007.

Almost all of the committee members are South American bishops. The others are two Vatican officials, Cardinal Peter Turkson and Archbishop Paul Gallagher; a nun, María Irene Lopes dos Santos, who represents male and female religious in the region; and a layman, Mauricio López, executive secretary of the Pan-Amazonian Ecclesial Network.

The synod is likely to address genuinely important matters of poverty and exploitation. But just as the 2014-15 synod was dominated by questions about divorce and Communion, it may well be that some very strange proposals about the priesthood will overshadow the 2019 meeting.