MPs from several parties have called for LGBT+ conversion therapy to be banned after thousands of people signed a petition on Parliament’s website.
In a Westminster debate, they heard stories of “medieval” and “harmful” practices which continue to be used.
The government said it was “committed” to “ending” attempts to suppress gender identity or sexual orientation.
But campaigners say they are still waiting for action, with people being exposed to psychological trauma.
The term “conversion therapy” refers to any form of treatment or psychotherapy which aims to change a person’s sexual orientation, ranging from electric shock treatment to religious teaching and discussion.
The practice is already outlawed in Switzerland and parts of Australia, Canada and the US.
MPs from across the political spectrum backed the ban during a debate in Parliament’s Westminster Hall, and called on the government for a timeline for the legislation.
Former Scotland Secretary David Mundell – the Conservative Party’s first openly gay cabinet minister – said the practice “could not be tolerated”.
He added: “Whilst I am sure that the government’s intentions are positive… the government has given the impression of being tardy and now is the time to end that impression.”
Many MPs spoke of of LGBT+ people who had been “left with scars” from the experience – as well as those who had taken their own lives.
Examples of the practice included people being told to starve themselves, being strapped to wooden chairs and being given electric shocks, while being gay was referred to as the “the deceit of Satan”.
The SNP’s Hannah Bardell said a friend of hers had revealed their experience of the practice, which led them to attempting suicide at the age of 12.
E-petitions are a way for members of the public to influence what is debated in Parliament.
Anyone can start a petition, as long as they are a British citizen or a UK resident.
When a petition passes 100,000 signatures, it is considered for debate by a cross-party committee of MPs.
Labour’s Angela Eagle called conversion therapy “medieval” and a “degrading and dehumanising practice”.
She said a ban should be an “obvious non-contentious step” to tackle “mistaken beliefs”, such as LGBT+ people being “a threat to society, that they are evil or disordered, that LGBT+ are ill or sick or can be cured”.
And Tory MP Elliot Colburn said: “We are not here talking about harmful practices that occurred some time ago. This is happening right here in the UK right now.”
He added: “With every day that passes, there is another person at risk at being subject to this degrading treatment and we risk losing even more lives of people who feel there is no other way out.
“As a gay man myself, and on behalf of LGBT+ people in the UK and around the world, [I want to say] we are here, our existence is real, our lives are valid and we cannot and do not need to be cured.”
The petition, which attracted more than 250,000 signatures, said running conversion therapy treatments in the UK should be made a criminal offence, as well as forcing people to attend or sending them abroad for them.
Boris Johnson said in July that the practice was “absolutely abhorrent” and had “no place in this country”.
The government commissioned research into the band – which was first proposed by Theresa May in 2018 – but ministers have yet to publish details.
In December, more than 370 religious leaders from around the world added their voice to calls to outlaw the practice.
Responding to the Westminster Hall debate, Equalities Minister Kemi Badenoch said: “I want to assure you that we are committed to ending conversion therapy in the UK and we take this issue very seriously.”
She added that “this practice has no place in civilised society” it was “shocking to think” it still went on.
A “robust criminal law framework” was in place to deal with the worst examples, the minister said, adding that people could face charges such as rape or grievous bodily harm in some cases.
But Ms Badenoch said the government did not want to stop those who “seek spiritual counselling as they explore their sexual orientation”.