An ex-gay Christian has decried the "monoculture of intolerance" around therapy and support for people with unwanted same-sex attraction or gender confusion.
Mike Davidson, CEO of the Core Issues Trust, said that intolerance towards counselling choice on the issue of gender identity and same-sex attraction had become "enshrined" in the media and therapeutic sector.
He said this was down to the Memorandum of Understanding on Conversion Therapy (MOU) issued several years ago by the British Association for Counselling and Psychotherapy (BACP).
Signed by 20 health, counselling and psychotherapy organisations, the document calls for an end to the practice of conversion therapy in the UK on the grounds that it is "unethical, potentially harmful and is not supported by evidence".
The Professional Standards Authority - the regulatory body for counselling organisations - has since 2015 refused to accredit any service that offers this form therapy.
But Mr Davidson says the MOU has become the "unquestioned, received wisdom" on conversion therapy to the detriment of the "rights and freedoms of autonomous individuals both to seek and offer assistance when same-sex attracted or gender confused persons seek help".
The media and counselling services "now without exception refuse to acknowledge fluidity in sexuality and the fact that some people move away from LGBT identities and practices that no longer serve them," he said.
Mr Davidson is calling on the Government to review this understanding of conversion therapy in light of a debate in Parliament last week in which some MPs suggested a ban should encompass prayer.
"Many people have mixed attractions. Government policy should not therefore favour or impose gay-affirming therapies, nor to deny former LGBT persons the right to professional help to achieve their goals," he said.
"We are concerned that the Professional Standards Authority (PSA) has refused to allow those who support therapeutic and counselling choice in these matters, to create an accredited register accountable to agreed standards in the UK.
"For this reason, former LGBT persons and those no longer LGBT identified have been denied support that should be regulated by the PSA.
"We communicated our concerns to the government's Cabinet Office in 2018 (link below), but have yet to receive any response.
"We wish to affirm the many former LGBT persons who experience transformation and change in their lives."
The Government said last week that it is committed to banning conversion therapy but the Evangelical Alliance has since urged "caution", warning that this would pose a "direct threat to religious liberty".
Other opponents of a ban include The Christian Institute and Christian Concern.