More than 370 religious leaders from around the world including South African cleric Archbishop Desmond Tutu and former Chief Rabbi of Ireland David Rosen, have called for a ban on gay conversion therapy.

The term “conversion therapy” refers to any form of treatment or psychotherapy which aims to change a person’s sexual orientation or to suppress a person’s gender identity.

The declaration calls for “all attempts to change, suppress or erase a person’s sexual orientation, gender identity or gender expression – commonly known as ‘conversion therapy’ – to end, and for these harmful practices to be banned.”

The therapy can range from electric shock treatment to religious teachings or talking therapies designed to change someone’s sexuality.

The practice is already outlawed in Switzerland and areas of Australia, Canada and the US. The close to 400 signatories calling for an end to the declaration represent all the world’s major faiths and many are known LGBT advocates.

A declaration calling for a ban will be launched at a conference sponsored by the Foreign, Commonwealth and Development Office (FCDO) on Wednesday, December 16.

The Anglican Bishop of Liverpool, Paul Bayes, and Mary McAleese, the former president of Ireland, are also among those who have signed the declaration”

Prime Minister Boris Johnson previously repeated a promise to ban conversion therapy, saying in July that the practice was “absolutely abhorrent” and “has no place in this country”.

One of the shortfalls stopping the UK government from banning Conversion therapy concerns the definition of the term “conversion therapy” and how it relates to all LGBT people.

Government figures have shown that trans people undergo conversion therapy at the highest rate of any LGBT group, but government fears changes could exclude conversion therapy based on gender identity and only focus on sexuality.

A 2018 survey of 108,000 members of the LGBT community in the UK suggested 2% have undergone the practice, with another 5% having been offered it.

Many global faiths, including Christianity, Islam and Judaism have traditionally taught that any sex outside of heterosexual marriage is wrong.

Peter Lynas, UK Director of the Evangelical Alliance which represents 3,000 churches in the UK, says he supports an “end [to] extreme and coercive behaviour without banning change or conversion, which are central to Christianity”.

He told the BBC a ban could risk “criminalising counsellors, pastors and even those asked to pray with people.”

Sheikh Ramzy, an Islamic scholar and founder of the Oxford Islamic Information Centre, said it was important imams were allowed to offer “help” if gay Muslims wanted to change their sexual orientation.

“We want to help them and not to damage them,” he told the BBC.