They call for the Synod to be given responsibility for authorising the Prayers of Love and Faith under Canon B2, for which final approval by a two-thirds majority in each of the Synod's three Houses would be necessary.

"Disunity" and "disrepute" will befall the Church of England if the Bishops do not go down this route, the letter argues.

In February, the proposal to allow blessings for same-sex couples was carried in all three Houses, but achieved a two-thirds majority only in the House of Bishops (News, 10 February). Seeking authorisation under Canon B2 would be likely to delay permission to use the prayers, and could end in their outright rejection or significant amendment.

The letter argues that "introducing a suite of liturgical resources for those in same-sex partnerships can be done fast or it can be done well. But it cannot be done both fast and well.

"This proposition of a better way forwards is still honouring the spirit of the vote at February's General Synod. It is not about rowing back from what was voted on."

The signatories, none of whom represents an organisation that has publicly supported the introduction of the prayers, assert that failure to adopt this route would "deprive Synod of its deliberative function and collective stewardship of such important matters".

They refer to the legal opinion of a barrister, Dr Edward Morgan KC, who "states that any alternative route is likely to expose the Church of England, the Archbishops, and the Diocesan Bishops to significant legal challenge".

A note at the foot of the letter, which has been sent to every bishop in the C of E, states that "all signatories are leaders of networks/organisations, but are signing in their personal capacities, recognising they cannot claim to speak for everyone that they lead."

The signatories include current and former Vicars of Holy Trinity, Brompton, the Revd Archie Coates and the Revd Nicky Gumbel; the chair of the Prayer Book Society, Bradley Smith; the newly installed National Leader of New Wine, the Revd Dr Rich Johnson; the executive director of the church-planting initiative MYRIAD, the Revd John McGinley; the Ministry Director of Living Out, Ed Shaw; and the President of the Church of England Evangelical Council, the former Bishop of Blackburn, the Rt Revd Julian Henderson.

The Prayers of Love and Faith were initially put forward by the College of Bishops in January (News, 20 January). It became clear that, although a motion would be brought to the Synod in February, a positive vote by the Synod was not strictly necessary for the prayers to be commended by the Bishops (News, 20 January).

The Bishop of London, the Rt Revd Sarah Mullally, said at the time that the Bishops were "proposing a way forward which gives us the opportunity to do as much as we can, in a way that we want seek views from Synod, but actually doesn't require legislation".

She continued: "We want to hear from Synod, and then having heard from Synod we will commend prayers for the blessing of same-sex couples."

Canon B5 gives ministers discretionary power to use forms of service provided that they are "neither contrary to, nor indicative of any departure from, the doctrine of the Church of 7/5/23, 6:11 PM Church organisations urge Bishops not to commend blessings for same-sex couples

The material was, none the less, fiercely debated in the Synod, and carried only after a proviso was added, in an amendment, that the Church of England was not changing its doctrine of marriage.

A slightly modified version of the prayers is due to be presented at this month's meeting of the Synod in York, but without an opportunity for a debate or a vote (News, 23 June).

New pastoral guidance for clergy and Readers, and measures to "reassure" those who object to the use of the prayers, are expected to be debated in the Synod in November.

The update paper, released with the Synod agenda (News, 23 June), says that the Bishops have "considered the range of routes" for making the prayers available for use. The paper continues: "They are particularly weighing up the option of approval by the Archbishops (under Canon B4.2), as an approach that may provide more legal protection for those ministers who choose to use the Prayers."

Applying Canon B4.2 would put the use of the prayers on a more formal footing, but without requiring the full synodical process.

The update states that "no final decision has been made by the House [of Bishops] as to the route by which the prayers will be made available for use."

END