The Church of England has agreed that gay clergy in civil partnerships can become bishops so long as they remain sexually abstinent, a decision that looks likely to reignite one of the Anglican community's most bitter internal debates.

The decision was taken by the House of Bishops, the section of the General Synod responsible for church teaching. Evangelical Anglicans immediately signalled their opposition to the idea, leaving the church with the prospect of two simultaneous internal rows following the synod's decision in November to block women from becoming bishops.

A summary of the House of Bishops' meeting on the church's website said members considered an interim report from a group led by Sir Joseph Pilling, a retired civil servant commissioned last year to look into the church's attitudes to sexuality.

While the bishops said they would not issue more guidance on civil partnerships before the final report, they said being in a civil partnership was not necessarily a bar to becoming a bishop. The summary read: "[The House of Bishops] confirmed that the requirements in the 2005 statement concerning the eligibility for ordination of those in civil partnerships whose relationships are consistent with the teaching of the Church of England apply equally in relation to the episcopate."

The 2005 document gave guidance for clergy, for example if they were asked to bless civil partnerships, which had come into being the previous year. It also stated that the House of Bishops did not see being in a civil partnership as "intrinsically incompatible with holy orders" provided those concerned could give assurances the relationship was not sexually active, but did not extend this to bishops.

The change was welcomed by Jeffrey John, dean of St Albans, whose decision to stand down from his appointment as bishop of Reading in July 2003 amid an outcry from church conservatives sparked a near decade of frenzied debate. John is in a long-term relationship with another clergyman, which he has affirmed is celibate. The pair had a civil ceremony in 2006.

John said: "If it is genuinely true that all levels of ordained ministry are now more open to gay people than they were before, then this is a very good thing."

Shortly after John stepped down as bishop of Reading, the issue became still more contentious after the US Episcopal Church approved the appointment of the openly gay Gene Robinson as a bishop.

There has been speculation that bishops eventually felt under pressure to move owing to the possibility of John taking legal action on equalities grounds after he was passed over to become bishop of Southwark in 2010.

The decision was made in mid-December, with a summary of the meeting placed on the church website before Christmas. However, the key section was some way down the summary and was missed until now. A church spokesman said there had been no intention of burying the news.

Speaking on behalf of the House of Bishops, Graham James, the bishop of Norwich, confirmed the change. He said: "The house believed it would be unjust to exclude from consideration for the episcopate anyone seeking to live fully in conformity with the church's teaching on sexual ethics or other areas of personal life and discipline.

"All candidates for the episcopate undergo a searching examination of personal and family circumstances, given the level of public scrutiny associated with being a bishop in the Church of England. But these, along with the candidate's suitability for any particular role for which he is being considered, are for those responsible for the selection process to consider in each case."

The Rev Colin Coward, director of Changing Attitude, a group that campaigns for the church to fully accept gay, lesbian, bisexual and transgender people, said he gave the news a guarded welcome, in that it was significant but unlikely to prompt a rush of gay bishops.

He said: "I don't trust what they have said. I don't believe they are serious about opening the door to someone in a civil partnership becoming a bishop. I would only believe they are serious when it happens." Apart from John, Coward said, it was difficult to see any gay clergy being made bishops. "In effect this imposes something more strict on those who become bishops than those who become clergy. In practice at least half of the House of Bishops ignore the guidelines and do not ask clergy questions about celibacy, and many of them consciously put in place people in civil partnerships with the partner present and acknowledged as a partner. I can't see that happening to someone who's becoming a bishop."

Rod Thomas, chairman of Reform, a campaign group for Anglican evangelicals, said the change had not been agreed by the wider church. He told the BBC: "That would be a major change in church doctrine and therefore not something that can be slipped out in the news. It is something that has got to be considered by the General Synod."

Giles Fraser, the former canon chancellor of St Paul's Cathedral who contributes to the Guardian on faith matters, said the row over John in 2003 had ignited years of "culture wars" in the church.

He said: "This new ruling is an acknowledgement that there was no theological basis for this objection. But, pathetically, it comes 10 years too late." The continued insistence on celibacy remained wrong, he argued. "Celibacy is fine as a vocation, if chosen, but it is manifestly cruel to ban a human being from physical intimacy simply because they are gay."