By Robert Pigott
BBC religious affairs correspondent
The Church of England is holding its Synod meeting in York
The Church of England is accustomed to attacks on its unity on one front.
When its ruling Synod meets in York for its summer session on Friday, it faces a pincer movement by two deeply divisive issues.
The first is over an issue that is not even on the agenda.
A traditionalist member of the Synod, Paul Eddy, gained strong support for his motion calling on the Church to make the conversion of people of other religions - including Muslims and other sizeable minorities in Britain - an explicit part of its purpose.
Mr Eddy got more than 100 signatures supporting the motion at two successive Synod meetings, and says he was led to believe his motion would be up for discussion this weekend.
He claims it was suppressed for fear of offending people of other faiths, with whom the Church has a delicate relationship. Church officials say there was simply no room in a crowded agenda.
This dispute might have gone relatively unnoticed but for the events in Jerusalem last week - and the rally by some 800 traditionalist Anglicans in London on Tuesday.
Jesus Christ is the only way to salvation for me", he said, "but I don't want to impose that on other people
The Fellowship of Confessing Anglicans (FoCA) created in Jerusalem identified backsliding in the duty to convert people of other religions as part of the liberal drift they say is undermining a true understanding of the Bible's teaching.
The Church of England's "suppression" of a motion reiterating, what to these traditionalists is a fundamental Christian duty, and belief provides them with an opportunity to portray it as being among the liberals' rewriting the Bible to suit the convenience of contemporary circumstances.
But one liberal bishop, Stephen Lowe, who has worked hard to foster better relations with Muslims in particular, said it was a question of how the Church approached other religions.
"Jesus Christ is the only way to salvation for me", he said, "but I don't want to impose that on other people".
The Archbishop of Canterbury, Rowan Williams, has also firmly denied that the Church is in some way backing away from evangelism, but the dispute is likely to have an ominous outcome for Dr Williams.
At a special meeting on Monday, members of synod will be invited to sign the "Jerusalem Declaration", and it is a fair bet that traditionalist frustration over the disappearance of Paul Eddy's motion will act as a recruiting agent for FoCA.
Suppose FoCA were to get the signatures of the 100 or more members who backed the Eddy motion.
It would be presented as the support of a quarter of the non-bishop members of the Synod, and, by extension, of the wider Church.
That would provide the traditionalist alliance - with its ruling council of overseas archbishops - with a boost to its standing and influence in the "mother" Church of England it could barely have imagined a week ago.
As if that were not enough, another dispute threatens the Church's unity - over women bishops.
The Synod has already agreed in principle to ordain women as bishops, but it faces an awkward decision about how to treat traditionalists whose religious consciences will not allow them to serve under a women bishop.
Anglo-Catholics Anglicans base their objection on Jesus's choice only of men to be his immediate 12 apostles, the men who were given leadership of the early Church.
They point out that an unbroken chain of male bishops has led the Church since then.
They take the view that a man ordained by a woman might not be properly ordained, and might not in reality be a priest, a suggestion fiercely rejected by women priests and many others in the Church.
A week or so ago, 1,300 traditionalist clergy - including 11 serving bishops - wrote to the Archbishops of Canterbury and York threatening to leave the Church unless special measures were put in place.
Ideally they would like a number of over-arching non-geographical dioceses - havens for traditionalists, free of female bishops - to be pasted over the structure of the existing dioceses.
They fear that all they will get is a non-binding "code of practice" that simply urged existing bishops to make concessions to traditionalists.
The traditionalist Anglo-Catholic wing of the Church has dwindled in recent years, but it has one ace up its sleeve.
For the legislation to progress a two-thirds majority will have to be achieved among bishops, clergy and lay members of the Synod, and the Anglo-Catholics have found allies among the more numerous evangelicals.
They are likely to back the idea of opt-outs, partly to establish a precedent for them to escape a liberal bishop in the future.
Some of the evangelicals say the Bible teaches "male headship", the idea that men should lead the Church, and families too for that matter.
Ranged against the traditionalists is another powerful alliance, of women priests, and a middle ground that sees no reason for a Church that has accepted women priests to prevent women becoming bishops.
They too seem not to be in the mood for compromise.
Four thousand Anglicans - more than half of them clergy - wrote their own letter this week, arguing that any concessions for traditionalists would directly undermine the status of women bishops, in a way that would be discriminatory.
They said they would rather wait longer for women bishops than have them introduced under these conditions.
The battle lines have been formed, and the outcome could be both bloody and doomed to stalemate.