An advert due to run on London buses that promoted gay conversion therapy has been been banned following a public outcry.
The advert, which promoted therapies designed to help people reach their "heterosexual potential" were set to appear on London buses from next week, in direct response to a campaign advocating same-sex marriage.
However Transport for London said on Thursday evening that after initially green lighting the campaign it had decided to block them.
“This advertisement has just been brought to our attention by our advertising agency, CBSO and we have decided that it should not run on London’s bus or transport networks," TfL said.
"We do not believe that these specific ads are consistent with TfL’s commitment to a tolerant and inclusive London."
Religious groups Anglican Mainstream and Core Issues Trust, which both oppose gay marriage, said they bought the advertising space following a pro-gay marriage campaign from rights group Stonewall.
The adverts featured the slogan "Not gay! Ex-gay, post-gay and proud. Get over it" in a mirror image of Stonewall's flagship "Some people are gay, get over it" campaign.
According to the groups, London buses travelling on five different routes were due to carry the advert for two weeks from Monday 16 April.
They say that the Stonewall campaign, which was launched at the start of April, "implies the false idea that there is indisputable scientific evidence that people are 'born gay', and that they have no choice but to affirm their homosexual feelings".
The groups also warn against the "misleading and dangerous" effects of the "promotion of homosexual practices to children and young people" and that people should be "supported in developing their heterosexual potential".
Dr Mike Davidson, the director of Core Issues Trust, said those campaigning in favour of gay marriage "ride roughshod over individuals who by conscience reject the simplistic notion that their choice to move out of homosexuality is because of internalised prejudice taught by society, completely ignoring the profound effect on sexual identity, established by highly respected scientific study, of childhood experience."
And Canon Dr Chris Sugden, executive secretary of Anglican Mainstream, said gay marriage was "prioritising adult sexualities" over the needs of children.
Stonewall chief executive Ben Summerskill said: "It’s sad that any self-styled 'Christian' group promotes voodoo 'gay cure therapy', which has been discredited by the BACP, the UK’s leading professional body for counselling psychotherapists."
He added: "Life would be much easier if these organisations just admitted that they don’t like gay people."
The Stonewall campaign in favour of gay marriage has been designed to tackle the "vitriolic political campaigning" from people opposed to same-sex marriage.
Summerskill said the campaign was a "very moderate and straightforward" and would help those who have been offended by anti-equality prejudice to tell the government why equal marriage is important to them.
The government is currently consulting on plans to introduce gay marriage and the plans have the support of the leadership of all three main political parties.
In reaction to the advert, London Liberal Democrat Mayoral candidate Brian Paddick said: "From personal experience as a gay Christian, I can tell you that it's much better to be out than in. We should be celebrating the diversity for which London is known for, not denegrating it.
"As Mayor I want to make London a place that is welcoming to all people, including Christians."
Ken Livingstone, also running for London Mayor, said the capital is "going backwards".
"The [Tory leadership] promotes a falsehood, the homophobic idea of ‘therapy’ to change the sexual orientation of lesbians and gay men. The adverts are insulting to LGBT Londoners and damaging for everyone who believes London is the greatest city in the world because of it's tolerance."
The campaign is not the first advert on London's buses to spark controversy: