The synod confirmed its decision to ordain women as bishops in 2008
Ordaining women as bishops would be "a mistake", a group of 50 clergy has warned in a letter to the Church of England general synod.
The clergy, linked to the evangelical group Reform, say adequate safeguards for objectors to the plan are needed.
If not, the Church could see a drastic cut in the number of men training for the priesthood and a multi-million pound drop in funding, they warn.
The general synod began its week-long meeting on Monday.
In the letter, the group demands special bishops are created to minister to parishes and clergy who object to women bishops with powers to ordain and approve the training of priests.
Chairman of Reform, the Reverend Rod Thomas, of St Matthew's Church, Elburton, Plymouth, heads the list of signatories.
He said: "For those of us ordained since 1992, our understanding, in good faith, was that proper legal provision would be made for those who did not agree that women should have the overall leadership of a church.
Religious Affairs correspondent
The Church of England's battle about how to introduce women bishops intensified on the opening day of the synod meeting.
The Bishop of Manchester announced that the committee trying to find a compromise on the issue was not likely to offer any real concession to traditionalists who are desperate to avoid serving under a woman.
Meanwhile an open letter went to every member of the synod from conservative evangelicals in the group Reform, considerably raising the stakes in the debate.
The Reform letter says conservative evangelicals could set aside some of the considerable funds they raise each year to fund a possible future outside the Church of England.
Financial independence would give conservative evangelicals a powerful bargaining chip in the stormy debate on women bishops still ahead.
It's also yet another sign that the old Catholic-Protestant divide in the Church is less potent than the growing gulf between conservatives and progressives.
"It seems to us a matter of simple integrity that synod should now keep its word to us in this and not force us down a road none of us wish to tread."
The signatories said that over the last decade their congregations had sent more than 180 men into ordained ministry, as well as contributing more than £20m to the Church of England's finances.
They warn they would have have to encourage new potential trainee priests to consider training for ministry outside the Church of England - and help pay for them if safeguards are not made.
Members of the general synod, meeting in London, heard a presentation from the Bishop of Manchester, the Right Reverend Nigel McCulloch, about the "daunting task" of drawing up legislation on the issue.
The meeting was told that a key debate on legislation to introduce women bishops will be delayed until July after hundreds of submissions were received on the subject.
He confirmed that members of the group had so far rejected the proposals to create new dioceses or a special class of bishops with statutory powers to minister to those opposed to women bishops in the Church.
The group believed any arrangements to cater for objectors should be on the basis of delegation from the diocesan bishops, he said, which is a move already condemned by traditionalists as inadequate.
He said members of the revision committee working on the move now hoped to complete their task in good time for the general synod to consider the proposals at its July meeting in York.
Christina Rees, of Women and the Church, which campaigns in favour of women bishops said: "We have already tried our best to keep everyone in (the Church) and to increase the level of communion between those who hold different views on women's ministry.
"It will be very important that once the law is passed that women are bishops in the Church of England that it is accepted and recognised as such.
"Therefore, of course there will be arrangements that will make it possible for individuals who disagree with women's ordination to stay in - but the thought of having a separate strand of bishops is precisely what the general synod debated and rejected over a year ago."