A religious group behind adverts promoting gay conversion therapy is taking action against the Mayor of London after the posters were banned from going up on London's buses.
Reverend Lynda Rose, a spokesperson for the Christian group Anglican Mainstream told The Huffington Post UK they were suing the Mayor of London and Transport for London (Tfl) for "breach of contract."
Boris Johnson said he had intervened to have the adverts pulled, telling the Guardian London was "intolerant of intolerance."
"It is clearly offensive to suggest that being gay is an illness that someone recovers from and I am not prepared to have that suggestion driven around London on our buses."
TfL announced they were pulling the ads on Thursday evening that after initially green lighting the campaign, which called for people to reach their "heterosexual potential" through gay conversion therapy.
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.
Dermot O'Callaghan, member of Anglican Mainstream and Core Issues told The Huffington Post UK that Boris Johnson had gone "a bit over-the-top".
"Boris Johnson says that he is intolerant of intolerance but the press release says the organisations who are involved in this action recognise the right of individuals to identify as gay and to live according to their own values. If that counts as intolerance then the nation as a whole is being branded as intolerant.
"I don't personally feel offended [by the Mayor] but I think it's very sad that he is jumping on a bandwagon and making intolerant statements.
"I think that he has gone a bit over-the-top. He's not allowing a level playing field."
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."
Stonewall chief executive Ben Summerskill condemned the ads, saying: "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."
A TfL spokesperson said: "This advertisement was brought to our attention yesterday afternoon by our advertising agency, CBSO and we have decided that it should not run on London’s bus or transport networks. We do not believe that these specific ads are consistent with TfL’s commitment to a tolerant and inclusive London.
"The adverts are not currently running on any London Buses and they will not do so."
The campaign is not the first advert on London's buses to spark controversy: