An independent Roman Catholic newspaper in the United States called for a campaign to reverse the Vatican's refusal to allow women to become priests.

"Barring women from ordination to the priesthood is an injustice that cannot be allowed to stand," the National Catholic Reporter said, waving a red flag in front of the Vatican over one of its most strongly held teachings.

The call to the priesthood "is a gift from God," it said, and excluding women from responding to that call "has no strong basis in Scripture or any other compelling rationale."

With bishops and theologians on record as opposing women's ordination, the Missouri-based biweekly -- a respected voice of the Church's reformist wing -- said it now fell upon the faith's rank and file to press for change.

"We must speak up in every forum available to us: in parish council meetings, faith-sharing groups, diocesan convocations and academic seminars," it said. "We should write letters to our bishops, to the editors of our local papers and television news channels."

There was no immediate reaction from the US Conference of Catholic Bishops, which toes a conservative line on other hot-button issues such as abortion, contraception and gay marriage.

The United States has the largest Catholic population of any rich country, with a quarter of its 310 million people belonging to the faith -- a proportion sustained by Latino immigration.

The editorial was prompted by last month's excommunication and expulsion of Father Roy Bourgeois from the Maryknoll order for his role in a women's ordination ceremony in Kentucky in 2008.

In a statement on November 19, the order said Bourgeois, a priest for 39 years, had acted "without the permission" of local bishops "while ignoring the sensitivities of the faithful across the country."

"Disobedience and preaching against the teaching of the Catholic Church about women's ordination led to his excommunication, dismissal and laicization," it said.