A US Episcopal Church bishop has given the go-ahead to priests in his diocese to conduct same-sex marriages without asking his permission first.

The bishop of the Episcopal Diocese of Mississippi, Rt Rev Brian Seage, announced the move in a letter to churches.

He said: "This significant modification of our former Diocesan policy means that parishes and missions are no longer required to engage in a process of discernment and study, culminating with formal vestry action and submission to me of a petition requesting approval to perform same-sex weddings."

However, Seage said that any priest was free to decline to marry a same-sex couple and would not face disciplinary hearings. He said: "My only request is that you refer, to me, any same sex couple seeking marriage, so arrangements can be made to offer these services of the church."

Addressing LGBT Episcopalians in his letter, Seage asked them "to continue to have patience with me and our church" on the issue of marriage.

"Please know that even if you have worshipped in a specific church for years, and are active in their ministry, there remains the possibility that the church and priest may be unable to officiate at your wedding," he wrote. "Please find a way to be patient with them as they work with me to find a priest willing to solemnise your marriage."

The Episcopal Church (TEC) voted overwhelmingly in favour of allowing same-sex marriage last year in a move that rocked the Anglican Communion and saw a crisis meeting of primates from across the Communion impose sanctions on it. It agreed then that authorised liturgies that would include same-sex marriages were "only to be available under the discretion and with the permission of the diocesan bishop".

The issue has proved excruciatingly difficult for the Anglican Communion. Earlier this month the leader of worldwide evangelical Anglican Christians accused the Church of England of "normalising" the "false teaching" of the US Episcopal Church over gay marriage because of the appointment of an American bishop who supports blessing same-sex unions to a post in the Liverpool diocese.

Archbishop of Nigeria Nicholas Okoh, chairman of the Global South orthodox Anglican group Gafcon, said a "line has been crossed".

The Akure diocese in Nigeria, which was twinned with the Liverpool diocese, has also formally severed its links following the appointment of Susan Goff, a suffragan in the Virginia diocese in the US Episcopal Church, as an honorary bishop in Liverpool.