The Church of England's national assembly has been warned of the "devastating" blow to morale if legislation introducing the first women bishops fails to be given final approval.
The Rt Rev Nigel McCulloch, Bishop of Manchester, said the measure before the General Synod had imperfections and there were "understandable" concerns from those opposed to the ordination of women.
But he said he believed the legislation would allow the Church of England to flourish and enable women to exercise leadership which many recognised as "God's gift" to the Church.
Failing to allow the legislation to clear its final hurdle would do "real harm" to the credibility and mission of the Church of England to the people of this nation, he said.
"If this legislation goes down after all the work and hopes of the past few years, it would be a shock to a large number of people across the Church of England," he told the General Synod.
"It would be a devastating blow to the morale of many, not least our female clergy. It would be a major deterrent to continuing to attract into the ordained ministry able women - and many able men too," he said.
But Canon Simon Killwick, a vicar in Moss Side, Manchester, in Mr McCulloch's diocese, and chairman of the Catholic Group in the General Synod, urged members to vote against the legislation.
"I do not believe that this draft legislation will be good for the Church of England," he said. "We are all desperate to move on from the sad infighting of the last few years - but this legislation does not provide a clear way forward."
Both clerics were speaking at the start of the debate, billed as the most significant decision to be taken by the General Synod in the 20 years since it first backed the introduction of women priests.
The debate and vote later on Tuesday follow years of complex negotiations on how to introduce women bishops within the Church of England amid opposition from traditionalists including some Anglo-Catholics and conservative evangelicals.