Churches around the world are softening their position on transgender people, according to a study by a Cambridge University academic.

The issue was highlighted earlier this year with the high-profile transition of US Olympian Bruce Jenner to Caitlyn Jenner, which caused a furore among conservative Christians. 

However, Rev Duncan Dormor of St John's College examined the positions of major Christian denominations and found that a growing number of Churches around the world are taking an inclusive approach.

Dormor undertook the study as his contribution to a book, The Legal Status of Transsexual and Transgender Persons. He says he has identified "a slow, sometimes grudging, but growing momentum for change among Christians within Protestantism especially".

The Church of England, Lutheran denominations in Scandinavia, and numerous Churches in the United States are described as leading the shift towards a state of broad-based acceptance in which transgender people are able to minister, teach and marry, though conservative Christian groups have remained fervently opposed. They have mounted fierce campaigns against inclusive civil rights ordinances brought in by cities including Houston, where Mayor Annise Parker was defeated in her attempt to bring in equal rights legislation. 

At the same time, the study acknowledges that the Roman Catholic and Orthodox Churches remain officially opposed to transgenderism. "The overwhelming majority of the 2.1 billion Christians in the world belong to Churches which are officially unsympathetic to the claims of transgender people," it observes.

The study suggests that many Churches have, within the last few years, become far less conservative on transgender issues than is traditionally assumed.

The study adds: "The ministry and marriage of transgender Christians has as often been grudgingly accepted as positively embraced, mostly within the last decade, and frequently in the face of significant unease of internal opposition. Nevertheless, there is growing momentum for change; for acceptance and welcoming of transgender Christians."

The challenge transgenderism poses to some Christian denominations is rooted in "theological anthropology" – a faith-based understanding of the human condition and what the difference between the sexes means. Many conservative Christians believe that God created human beings in two distinct forms – male and female – and that these differences are an essential characteristic of what it means to be human.

The research singles out changes within the Church of England. Even though a clear position on transgenderism has yet to be drawn up by its governing body, the General Synod, there are currently at least eight transgender priests serving within the Church, of whom six were ordained prior to transition.

While the Church secured an exemption under the Gender Recognition Act of 2004 for clergy who did not wish to solemnise the marriage of transgender people, the survey points out that it also protected the rights of transsexual parishioners to use their parish church.

Furthermore, when the Act was debated in the House of Lords, a number of bishops played a vital role in preventing the progress of an amendment that would have given religious bodies greater power and autonomy to restrict the participation of transgender people in the Church.

"The developing positions of these Churches illustrates that religion's perspective on transgenderism is less monolithic than is sometimes believed," Dormor said. "It is important to remember that it is plural and accommodates a diversity of views. It seems highly likely that the developments we have seen over the last decade or so will continue."

The report acknowledges that similar developments are unlikely to take place in the Catholic Church, which remains formally opposed to transgenderism. It does, however, suggest that unofficially the Church's attitude towards trans people may soften under Pope Francis, compared with his two predecessors, John Paul II and Benedict XVI.

"Gender is one area in which Pope Francis to some extent represents intellectual continuity with the previous two Popes, but unlike them he does not see gender in exclusively ideological terms," Dormor added.

"People or communities who are marginalised or suffering are a priority for him. That means that while the Catholic Church will continue to fight the EU on gender legislation, it may simultaneously become more responsive to groups of people and individuals who need to be supported because of their marginalised status."