The TEC's House of Bishops voted 88 - 35 in a closed meeting in Salt Lake City on Thursday to remove Bishop Robert Duncan from ordained ministry on the grounds of "abandonment of the communion of this church". There were four abstentions.
Duncan, who has led the Episcopal Diocese of Pittsburgh for 11 years, is the moderator of the Common Cause Partnership, a network of Anglicans in North America disenchanted with the The Episcopal Church's pro-homosexual agenda and moving to break away from the liberal denomination.
His deposition comes ahead of the Diocese of Pittsburgh's vote on October 4 on whether to secede from the The Episcopal Church and align instead with the more conservative Anglican Province of the Southern Cone in South America. The Pittsburgh Diocese said it will move ahead with the secession vote despite Duncan's removal.
In a joint statement, Dr Philip Giddings, Convenor of Anglican Mainstream, and Canon Dr Chris Sugden, the group's Executive Secretary, said, "To take such action is hardly in the spirit of the reflections at this year's Lambeth Conference or the Archbishop of Canterbury's final presidential address.
"We see this vote as further evidence that The Episcopal Church in the USA in its formal decisions and structures 'have denied orthodox faith'."
Bishops at the Lambeth Conference held in Canterbury in July and early August agreed an immediate halt to homosexual consecrations, blessings for same-sex unions, and cross-border interventions. The Archbishop of Canterbury, Dr Rowan Williams, spoke in his final address, meanwhile, of the desire among bishops to remain in communion and continue working towards a unifying covenant.
Dr Giddings and Dr Sugden were among the hundreds of conservative Anglicans who met in Jerusalem in June for the Global Anglican Future Conference (GAFCON) to assess the future of orthodox Anglicanism and the Anglican Communion.
The two leaders pointed in their statement to the Jerusalem Declaration issued by GAFCON leaders at the end of their conference, which stated, "We reject the authority of those churches and leaders who have denied the orthodox faith in word or deed. We pray for them and call on them to repent and return to the Lord."
Dr Giddings and Dr Sugden added, "Anglicans who adhere to the orthodox faith will continue to welcome and receive the ministry of Bishop Bob Duncan as a faithful Bishop and wish him and the people of the Diocese of Pittsburgh the Lord's blessing in their faithful witness to the gospel."
The orthodox Convocation of Anglicans in North America (CANA) also said it would continue to recognise Bishop Duncan as a bishop of the Anglican Communion, as Bishop of Pittsburgh, and as the moderator of the Common Cause Partnership.
CANA Missionary Bishop Martyn Minns denounced TEC's "hostile and uncanonical action", saying it would not be accepted by the worldwide Anglican Communion.
"We hope and pray for the leaders of The Episcopal Church that they would protect the interests of its members by working with - rather than fiercely against - its bishops to proclaim the life-transforming news of the Gospel of Jesus Christ. That should be the goal of all Christians. Sadly, trying to fire a bishop in good standing with the rest of the Anglican Communion does nothing to save one soul," Bishop Minns concluded.