Vatican: Nice-guy Pope Francis looks set to have his mettle tested by his first mutiny in the ranks this weekend at a Catholic meeting on the contentious issue of traditional marriage.
The Church has long refused to relax rules for "sinners", but amid a flurry of countries legalising same-sex marriage and a rise in divorce levels, reform-minded Francis has suggested there may be wiggle-room on doctrine, sparking panic among conservatives.
Hundreds of bishops will attend the October 5-19 synod at the Vatican and tensions are running high after weeks of heated sparring.
"On the one side there are those who fear openness will result in the Catholic doctrine crumbling away, and on the other there are those who are waiting for big news and may be disappointed," Iacopo Scaramuzzi, Vatican expert for TMNews, told AFP TV.
Francis said last year that it was time to "re-examine... rules or precepts" and "certain customs" in the Church, calling for generosity towards wayward believers.
Then in February his close ally German Cardinal Walter Kasper, tapped by the 77-year-old to address the world`s cardinals on hot-button issues, sparked further controversy by calling for a more "merciful" approach to remarried Catholics who want to take communion, the main sacrament for Catholics.
Ignoring the cacophony of outraged voices, Francis went a step further last month by marrying couples in Saint Peter`s Basilica who had been "living in sin", as the Church terms unmarried people cohabiting and unmarried mothers.
He also repeated his concerns that unwed mothers and their children are not finding the compassion they deserve from a stony-hearted Church.
A group of prominent conservatives hit back this week in a letter to the pope which urged him to uphold traditions and resist laws that redefine marriage, as recent legislation on gay unions has done in many countries.
A book by five rebel cardinals demanding the Church stand firm on remarried Catholics threw Francis into a fury, according to sources close to the Vatican.The pope "has not mastered the media machine on remarried divorcees and Cardinal Kasper`s adversaries have managed to occupy the field," said Vatican expert and author Nicolas Diat.
With tension mounting, the pope warned of "very dangerous bombs" in the Vatican which "threaten the life of the Church" and reminded would-be trouble makers that "division within a Christian community is a very grave sin, it is the work of the devil."
There is no doubt among experts that gay marriage will be strictly off the table at the talks, as will abortion. At the heart of the debate will be the question as to how remarried divorced people can receive communion when they have broken their promise to God.
But critics say the rule treats remarried divorcees worse than criminals, because a convicted mafia gangster can receive communion after absolution by a priest, whilst a divorced mother cannot if she marries a new partner.
Francis set off alarm-bells among traditionalists last year with an unprecedented questionnaire on family issues which asked bishops for parish-level input on issues such as contraception, same-sex marriage and divorce.
Many bishops shifted the burden to local priests, however, and most declined to reveal the opinions canvassed from individual Catholics, shying away from the public debate sought by the pope.
Experts have warned against expecting a change in Church doctrine from this synod, which is only aimed at getting the ball rolling. A second meeting in a year`s time will be used by the bishops to begin putting in place a pastoral plan which should reflect earlier deliberations.
But with a very limited number of women, married couples and lay people invited to take part, the Church has been accused -- once again -- of entrusting the future of the Catholic family to the hands of celibate men.