Channel 4 is to broadcast an advertisement for the Alpha Course, an evangelical programme run by Alpha UK, who promote the idea that homosexuality is a sin.
The Alpha Course is a ten-week programme designed to introduce students to Christianity.
The advertisement forms part of a major campaign by the Alpha UK group, which is renowned for its conservative approach.
According to John Rose, who wrote an essay on the Alpha course attitude to homosexuality for the Gay and Lesbian Humanists Association (GALHA), the course text espouses the sinfulness of homosexuality, AIDS as a judgment from God and the exorcising of homosexuality.
The text states that: "He [God] did not design our bodies for homosexual intercourse."
Rose adds that in his Alpha course sessions, Nicky Gumbel, spiritual leader of the Alpha course, compares homosexuality to paedophilia.
According to Rose, the Alpha course advocates the idea that homosexuality involves "shameful lusts," and labels homosexuals as "homosexual offenders."
In a Guardian news article, Gumbel also stated that "gay people need to be healed".
The advert will be shown in the first commercial break in the Channel 4 drama Brothers and Sisters tomorrow night.
The US drama series has been widely praised for its realistic portrayal of gay characters.
The commercial was first shown on the digital channel E4 last week, but showing it on terrestrial television could reach a post-watershed audience of 2 million viewers.
The advertisement will be broadcast 58 times on the digital channels E4 and E4+1 and, from yesterday until next Friday, it will be shown at 2,200 cinemas across the country. It will also be shown on screens in London's double-decker buses and in pubs and bars.
Mark Elsdon-Dew, a spokesman for Alpha UK, told The Independent: "We step up our advertising every September because that's when we have the most courses running and, as a result, have both the most attendees and the most places to fill.
"We have not changed our advertising budget for this year at all. We have just cut out billboard advertising in favour of cinema and television screens, which have a much wider reach."
The 60-second advertisement shows an adult heterosexual couple on a conveyor belt from birth to death and ends with the catchphrase: "Is there more to life than this?"
Other religious movements – including Scientology and the Mormons – have advertised on British screens before but this is the first time a mainstream evangelical Christian movement has used television to attract newcomers.
A spokeswoman for Channel 4 told The Independent that the Alpha UK advertisement met industry guidelines.
The Alpha course has received much criticism from various different quarters.
From within the Christian church it has received criticism from both the evangelical and liberal wings, for its non inclusive stance and psychological manipulation techniques used to convert members.
In March 2006, PinkNews.co.uk reported that gay Pop Idol winner, Will Young, had completed the Alpha Course.
Terry Sanderson, Vice President of the National Secular Society and activist in the Gay and Lesbian Humanist Association told PinkNews.co.uk that he was surprised that the star has joined the controversial group: "I am shocked, that someone like this would do this. People can do all sorts of things that can damage them, alpha can be one of these."
Mr Sanderson, who has long criticised the Alpha course said that it is "fundamentalism wrapped up in pretty paper, well marketed but at base fundamental. It is completely anti gay. Those who are gay on the course do not get told this until it is too late.
"Any gay person who gets involved in this will find their basic personality will be challenged. When they have completed the course they are invited to a weekend where they are held in isolation. They call it the Holy Spirit Weekend and they are encouraged to become possessed with the holy spirit and speak in tongues."
Responding to claims that millions of people have attended the course, Mr Sanderson said: "They talk themselves up into their big success, if they are converting millions why are so many empty?"