More than 100 United Methodist Church (UMC) clergy have come out as gay, lesbian, bisexual, transgender, queer and inter-sex ahead of the Church's General Conference this week.

A letter published on Monday by the 111 clergy accused the UMC of forcing clergy to hide their sexual identity.

"While we have sought to remain faithful to our call and covenant, you have not always remained faithful to us," the letter said.

"You have required that we not bring our full selves to ministry, that we hide from view our sexual orientations and gender identities.

"As long as we did this, you gladly affirmed our gifts and graces and used us to make disciples of Jesus Christ for the transformation of the world in the varied places you sent us."

It urged the UMC to welcome clergy of all sexual identities in its policies. "You cannot legislate against God's call," the letter added.

"The 'LGBTQI issue' is not one that can be resolved through restrictive legislation but instead by seeing that all persons are made in the image of God and welcomed into the community of faith."

The letter also urged unity in the midst of division. "Dear church, our prayers are with you, with all of us, in the coming days. May we all be surprised by the Spirit who continues to breathe new life in unexpected ways. May we find the body of Christ stronger at the end of our time together, not weaker or more deeply harmed. May we provide a powerful witness of finding unity even in our differences to a world fractured by fear and mistrust."

The letter was posted on the Reconciling Ministries Network (RMN) website, which crashed soon afterwards.

It comes a day before the UMC's four-yearly conference meets in Portland, Oregon, on Tuesday.

The UMC currently does not allow "self-avowed practising" gay people to be ordained, or same-sex marriages, and activists have been gearing up to promote the advancement of LGBTQ rights at the conference.

They want what they consider "discriminatory language" in the Book of Discipline – the law and doctrine of the UMC updated every four years – to be removed, for gay and lesbian ministers to be ordained, and for same-sex weddings to be performed in UMC churches.

Rev David Meredith, an elder in the UMC in West Ohio, married his long-term partner Jim Schlachter at Broad Street United Methodist Church in Columbus this weekend. There have been calls for his suspension.

Speaking to Christian Today, executive director of RMN, Matt Berryman, said the clergy who came out "are speaking to make themselves visible, and to shine a light on the injustice of this whole situation, and a Church that would utilise and benefit from the talent, skills and gifts of all people, but not allow them to be their full selves."

He said: "Being self-avowed and practicing as a gay person in the UMC is against policy – you can be removed from your job and lose your salary, so it's an act of courage and we hope that this act itself will affect a kind of change; it's an act of courage to break the system".

Berryman went on to describe the letter as "classic civil obedience", and said that recent surveys have shown the majority of UMC members are in support of same-sex marriage. RNM has seen more growth in the last four years than ever before, he said, and there has been a 40 per cent increase in the number of churches that are inclusive.

"The system is breaking down," he said. "The powers that be will need to come together to figure out a way to revise the present system to create new room for people to live and move and have their being in the Church."

The UMC is at a "point of crisis", he added. "The Church can't go on like this".

In a statement sent to Christian Today, president of the UMC Council of Bishops, Bishop Warner Brown Jr., said: "The United Methodist Church affirms that all people are of sacred worth and welcomes all people into its congregations. Legislation before General Conference will consider the denomination's stance on the ordination of clergy who identify as gay, lesbian, bisexual, transgender and other orientations.

"Any complaints about an individual clergy member are handled at the local annual conference level following procedures in the Book of Discipline."