The President of Gafcon UK, Bishop Michael Nazir-Ali, has said he is "very concerned" by the appointment of Stephen Cottrell as Archbishop of York.
Cottrell is the current Bishop of Chelmsford and will succeed Dr John Sentamu as Archbishop of York following his retirement in June.
The bishop's appointment has been met with alarm by some evangelicals because of a dispute in his diocese last year over a Church of England primary school's approach to transgenderism.
The dispute led to the resignation of the Rev John Parker as a governor at the school and as a vicar in the Church of England.
He claimed that the bishop had told him that he could leave the Church of England if he did not like its approach to sexuality.
Four conservative clergy in the Diocese of Chelmsford have resigned in the last year and others have come forward to publicly back Parker's claims.
"I certainly did not, as has been claimed, ask or imply that he should leave the Church of England on account of his views on the matter in question, or that he was not welcome," he said in a statement at the time.
But there have also been concerns over the bishop's views on sexuality, in particular a 2017 presidential address in which he discussed the subject.
"At the moment, there is no consensus in the Church of England for those relationships to be formally blessed in Church, or for the Church of England to embrace same-sex marriage, but the current arrangements do welcome lay people and clergy into civil partnerships and there is no reason why prayers of thanksgiving for these relationships – perhaps a Eucharist – cannot be offered," he said in the address, adding, "Therefore, let me be loud and clear on this issue: whether you believe there should be same sex marriage or the blessing of same sex unions or whether you do not, you are still a faithful Anglican."
Commenting on Bishop Cottrell's appointment, Bishop Nazir-Ali said that the bishop should publicly affirm the "universal teaching of the Church" on sexuality.
"We need to pray for the Church of England and for Bishop Stephen at this time because I am very concerned that someone who has openly argued and worked for a change in the Church's teaching on human sexuality should have been nominated to such a senior position," he said.
"I urge Bishop Stephen to publicly affirm the teaching of the Bible, the universal teaching of the Church, the Lambeth Conference Resolution 1:10 and the 1987 Resolution of General Synod on matters of sexuality. Without this, orthodox believers in the CofE will have to ask what place there is in this church for them."
The Church of England has defended the bishop's appointment, calling the accusations against him "entirely without foundation".
"It is untrue that Bishop Stephen suggested to a governor of a Church of England School that his views on sexuality were not welcome and he could leave," a spokesperson for the Church said.
"Bishop Stephen made that clear at the time and subsequently in an Ad Clerum. It is also untrue that Bishop Stephen suggested to any other clergy that they should leave the Church of England. As he is said at his announcement, the Church of England is a Church for all people, welcoming everyone.
"He upholds the teaching of the Church of England that recognises marriage as being between one man and one woman.
"Bishop Stephen has not endorsed gender transitioning in and of itself for children but has pastoral concern for any child affected by gender dysphoria."