A coalition supporting the gay and transgender members of the Anglican church is pressing for it to recognise the contribution made by those clergy without whom, it says, some parishes “would face utter collapse”.

The group advocates lifting the ban on bishops in civil partnerships and allowing priests free choice on whether to conduct such ceremonies in their churches, an issue currently being considered by a review group in the church’s House of Bishops.

Reverend Benny Hazlehurst, Chair of the LGBT Anglican Coalition, told PinkNews.co.uk the group would be handing out flyers outside the General Synod at a Silent Act of Witness tomorrow ahead of its meeting with the review group this month.

He said: “If all the LGB&T Clergy were to leave the Church of England, parochial and sector ministry in the Church of England would suffer major trauma, and the parish system in some parts of the country would face utter collapse.”

Rev Hazlehurst said the group estimated there are over 1,500 gay, bi or trans clergy in the country and the LGBT Anglican Coalition was advocating more recognition of these members.

In December 2011, the Church’s House of Bishops announced the creation of a review group to advise it on civil partnerships, chaired by the Bishop of Sodor and Man, the Rt Rev Robert Paterson.

The other two members of the Group are the Bishop of Portsmouth, the Rt Rev Christopher Foster, and the Bishop of Dorchester, the Rt Rev Colin Fletcher.

The Church of England said the group should report to the House of Bishops in time to reach conclusions this year.

In July, the House of Bishops had issued a statement saying, in part: “Over the past five and half years there have been several developments. Consistent with the guidelines in the Pastoral Statement a number of clergy are now in civil partnerships. The General Synod decided to amend the clergy pension scheme to improve the provision for the surviving civil partners of clergy who have died.

“More recently Parliament has decided that civil partnerships may be registered on religious premises where the relevant religious authority has consented (the necessary regulations are expected this autumn).

“The review will need to take account of this changing scene […] Within the Anglican tradition our theological thinking is formed by a reasoned interpretation of Scripture, within the living tradition of the Church informed by pastoral experience. The House believes there is a theological task to be done to clarify further our understanding of the nature and status of these partnerships.”

A number of London’s Anglican priests signed a letter asking for acknowledgement of the “growing number of clergy” in the capital who feel that whether to conduct the ceremonies is “a matter for the conscience” for priests.

The coalition’s Act of Witness will take place at the Dean’s Yard in Westminster, London tomorrow morning from 8.45 to 9.30am.

The LGBT Anglican Coalition comprises Accepting Evangelicals, Changing Attitude, The Clergy Consultation, Courage, The Evangelical Fellowship for Lesbian and Gay Christians, Inclusive Church, The Lesbian and Gay Christian Movement, The Sibyls and the General Synod Human Sexuality Group.