An anti-gay advert campaign promoting same-sex marriage and gay conversion techniques has been pulled from London buses, the Transport for London (TfL) confirmed on Friday.

The "gay-cure" campaign has been backed by religious groups, the Core Issues Trust and the Anglican Mainstream in response to an earlier advert campaigning same-sex marriage by the rights group, Stonewall.

The adverts by Stonewall started in April where around 1,000 London buses carried the group's flagship "Some People Are Gay. Get Over It!" campaign.

"In recent months Britain has been subjected to vitriolic political campaigning from people who want to impose their 19th-century values on 21st-century society," said Stonewall Chief Executive Ben Summerskill. "Our very moderate and straightforward campaign - which will be seen by hundreds of thousands of Londoners, and many more people online - will help those who have been offended by anti-equality prejudice to tell the government why equal marriage is important to them."

In response to this, the anti-gay campaign supported by the religious groups featured the "mirror image" of the Stonewall campaign slogan as "Not gay! Ex-gay, post-gay and proud. Get over it"

The organisers of the "gay cure" campaign believe that the Stonewall advert "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 Huffington Post reported. 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".

The non-profit Cristian organisation, Core is dedicated to support men and women with "homosexual issues" who voluntarily seek change in sexual preference and expression.

As per the organisation's website, their main vision is to "uphold Biblical standards and values and appropriate ethical principles in contemporary society, in which Christian churches have sometimes failed to act with compassion or understanding towards those who struggle to overcome."

According to the BBC, Boris Johnson, the Mayor of London and the Conservative candidate for mayor in next month's elections, said the suggestion that being gay was an illness was "clearly offensive" and added that he was "not prepared to have that suggestion driven around London on our buses".