The Church of England is to begin a key meeting to decide whether to give final approval for the first women bishops amid speculation that the historic move could be put on hold.
Members of the General Synod will gather at York University for five days of debates expected to culminate in a knife edge vote on Monday on whether draft legislation to introduce women bishops should clear its final hurdle before it goes to Parliament.
But the decision - the biggest in 20 years by the Church of England - could be postponed following protests from pro-women campaigners over a last-minute amendment to the legislation made by the Church of England bishops earlier this year.
A group of senior women clergy including the four female deans of the Church of England cathedrals and eight archdeacons have written to members of the General Synod asking them to adjourn the debate on final approval and send the amendment back to the bishops for re-consideration.
The dispute centres on complex arrangements to cater for parishes which would reject the authority of a woman bishop. Under draft legislation passed by 42 out of the 44 Church of England dioceses, a woman bishop would refer to a code of practice before delegating authority to a male bishop who would minister to objector parishes.
Senior female clergy and other campaigners have objected to a new clause in the legislation added by the bishops in May which says the code of practice must give guidance that male bishops chosen to minister to traditionalists have views about the ordination of women "consistent with the theological convictions" of objector parishes.
Pro-women campaigners have claimed this would enshrine discrimination against women in law, allowing traditionalists to demand a class of "pedigree" male bishop who have not been "tainted" by having ordained a woman as a priest.
The Rev Rachel Weir, of the group Women and the Church (Watch) called for an adjournment of the debate to allow the bishops to withdraw the controversial amendment.
"Over 4,000 people have already signed Watch's new petition asking for the House of Bishops to withdraw the amendment," she said. "It is clear that the legislation has lost the support of those who most want women as bishops and has not gained the support of those opposed. The amended legislation is at serious risk of falling if put to a final vote next Monday."
If the legislation clears the final hurdle at the General Synod on Monday, it will then go for approval in the Houses of Parliament before receiving Royal Assent, paving the way for the first women bishops in 2014.