Proposed changes to the Church of England's guidance on homosexuality fail to recognise gay people's "authentic voices", retired bishops have said.
In an open letter, the 14 former church leaders questioned a report published last month which recommended a "fresh tone and culture of welcome and support" for gay and lesbian people but no change in its opposition to same-sex marriage.
The report, by the House of Bishops, also drew criticism from the Lesbian and Gay Christian Movement over the suggestion both gay and straight men and women training to join the priesthood should face the same questions about their lifestyle - a move likened to a "Don't Ask, Don't Tell" policy.
The group of retired bishops broke with convention to intervene, in what they described as an "unprecedented move", ahead of a debate at the Church's General Synod on Wednesday.
Led by the former bishop of Worcester, the Rt Rev Dr Peter Selby, they said: "Our perception is that while the pain of LGBT people is spoken about in your report, we do not hear its authentic voice.
"Our experience would lead us to doubt whether there was an expectation around that canons and doctrinal statements would be changed within any reasonable timescale, and that focus seems to have taken far more time than it would have done if the authentic voices of lesbian and gay people had been allowed to express the major focus of their hopes."
While they said a change in doctrine was not "realistic", the report's focus upon it meant the church would be on the defensive.
The letter continues: "The result of that focus on the issue of a change in the law is that your call for change of tone and culture, while absolutely right, does not carry conviction.
"Indeed, from the perhaps luxurious perspective of retirement the tone and culture of your document are incredibly familiar - we've been there and talked in that tone of voice, and it prevents calls for a change of culture, of course offered in complete sincerity by you, from ringing true."
Gay members of the church community would feel "deep disappointment" that they were not given a voice.
Other signatories to the letter include the Rt Rev Lord Harries of Pentregarth, formerly Bishop of Oxford, and the Rt Rev Roy Williamson, formerly bishop of Bradford and of Southwark.
The Church has rejected the claims its plan would "formalise Don't Ask, Don't Tell".
The term is a reference to the former US military policy between 1994 and 2011 which barred openly gay or bisexual Americans from serving but did not discriminate against them if they did not disclose their sexuality.
Church leaders will gather in London for the four-day Synod, which starts on Monday.