The Evangelical Alliance has written to Prime Minister Boris Johnson to raise concerns about the "chaos and confusion" the government's latest decisions on the conversion therapy ban have caused.
Last week, a leaked document revealed the government had decided to drop plans to ban the practice and was looking to explore other non-legislative ways to stop it.
But an immediate reaction by the LGBT community, outraged by the decision, prompted the government to reverse its initial decision and explain that the legislation would be brought forward but only covering gay and bisexual people, excluding therefore the transgender community.
"The lack of clarity helps no-one," the Evangelical Alliance's letter read.
The body, which represents the UK's two million of evangelical Christians, argued that the government's initial decision not to proceed with a new legislation on conversion therapy "seemed to be the right outcome delivered in the wrong way".
"Many were encouraged to hear last week that: "Having explored this sensitive issue in great depth, the government has decided to proceed by reviewing how existing law can be deployed more effectively to prevent this in the quickest way, and explore the use of the other non-legislative measures."
"Within hours this position was reversed. It is difficult to see how months of legal scrutiny could suddenly be found wanting," the letter said.
The Evangelical Alliance is one of the Christian bodies worried about a potential criminalisation of Christian practices such as praying for someone with unwanted same-sex feelings or preaching a Christian traditional view of marriage and sexual ethics.
The letter continued: "Conversion therapy is an emotive topic.
"The lack of a clear definition adds to the confusion and often leads to those with different views talking past one another. For clarity, the Evangelical Alliance does not support disreputable practices claiming to 'cure' those who are gay or transgender."
This is the third known letter that Christian leaders have written to the PM this week on conversion therapy.
Christian ministers against the ban wrote asking for clarification and reassurance that the ordinary work of churches would not be criminalised in the ban.
Whilst, those in favour of the ban urged the government to include the Trans community in the upcoming legislation.