Vicars from the Church of England have threatened to find a way of bypassing the ban on the church performing same-sex weddings in upcoming marriage equality legislation, by blessing ceremonies held in other churches.

Campaigners from the Church of England have said that banning the church from performing same-sex wedding ceremonies would lead to worshippers and clergy marrying in Quaker and Unitarian services, before returning to the Church of England.

A letter to the Telegraph, which contains 150 signatures, said that gay Anglicans should do so, if the legislation on marriage equality goes through as it currently stands, with the ban intact.

Culture Secretary, Maria Miller told the House of Commons on Tuesday she was putting in place a “quadruple lock” of measures to guarantee religious organisations would not have to marry gay couples against their wishes. She also noted a ban on the Church of England, and Church in Wales performing same-sex weddings.

The letter from the Anglican campaigners, which included Lord Harries, the former Bishop of Oxford, read:

“Until the Church of England allows us to solemnise same-sex marriages in our churches, as a matter of pastoral expediency we will counsel lesbian and gay members of our congregations to marry in those churches willing to celebrate faithful same-sex relationships,”

In the letter, campaigners warned: “If the bill is enacted in its present form, in 2014 married lesbian and gay Anglicans, lay and ordained, will be worshipping and ministering in parishes of the Church of England.”

According to the letter, the intention is that the presence of gay, married couples, which would include members of the clergy, in the Church of England, would force its leaders to engage with the debate over sexuality in the church.

The letter concludes: “The Church of England needs to relinquish its exemption from the equal marriage bill and address the expectation of the majority in every parish that it will continue to offer pastoral care to every citizen, including gay married couples and their children.”

Faith groups such as the Quakers, and Unitarians support marriage rights for gay couples and have stated they would like to provide the ceremonies.

Reverend Colin Coward, Changing Attitude, a campaign group which represents more than 1,000 Anglicans, said vicars could offer blessings in local churches, after formal ceremonies had taken place elsewhere. He said:

“People long to be able to celebrate same-sex marriages in the sight of God and for that reason people will go to other denominations if the Church of England closes the door.

“There are many clergy around the country discretely offering services of thanksgiving and blessing for lesbian and gay couples and that will increase if the Church closes the door on equal marriage.

“They will do it because these will be members of their congregations who rightly want a religious service in their own parish church.”

As it stands, the draft legislation would allow religious institutions to be able to “opt-in” to performing same-sex weddings, except for the Church of England, or Church in Wales, for which it would be illegal.

The Church of England also said it only learnt of the government’s plan to ban it from performing same-sex marriages when Culture Secretary Maria Miller took to the Commons despatch box on Tuesday.

Dr Barry Morgan, Archbishop of Wales, said the announcement also came as a “total shock” to the Church in Wales. 

In a letter voicing her concerns with recently announced plans to bring forward legislation to allow marriage equality, Baroness Warsi has warned of potential ”unintended consequences” if the law were to change.