Christina Wright is the woman behind the first televised orgasm in the history of British advertising.

The 20-second condom commercial will show a couple having sex and zoom in on a female model's face as she is in the throes of ecstasy.

Christina, 28, from Burgess Hill, is the public relations whizz behind the Trojan condom advert.

She said: "When we first saw the ad we all went, 'Oh my God!'.

"I think it will do exactly what it needs to do, which is to grab attention and show people that sex with condoms can be great."

The advert, to be screened during the first break in the new series of TV reality show Big Brother, follows a poster campaign by Trojan which provoked a flurry of complaints - although none was upheld.

Posters can be seen at bus stops around Brighton and Hove featuring the posters, which show models' ecstatic faces.

But Trojan will have to go a long way to beat the most troublesome campaign in the Advertising Standards Authority's 40-year history which featured an advert with the logo: "Thou shalt always wear a condom".

It was dreamed up in 1995 by the British Safety Council and prompted 1,187 complaints.

Christina was the first face of the Trojan campaign - she had to put on her best orgasmic expression for the test shots when the idea was being sold to the company.

She said: "It's amazing what you will do for your clients. It is such a great campaign to work on, though."

Christina first got into public relations after helping a family friend with clients at the age of 13.

She set up PR4 in London three years ago after working as a freelance consultant.

Christina sees the new series of Big Brother as the ideal slot for a condom advert.

She said: "Big Brother Five undoubtedly has a sexual theme. People are asking if the contestants are going to get together and if they are going to 'do it'.

"So we immediately thought, what better slot could we get for a safe sex message?"

Sexual antics have spawned controversy in Big Brother series around the globe. At home the last series was panned because of the lack of nookie.

But bookmakers have already slashed the odds on sex on the settee in Big Brother Five - encouraged by two youngsters on a teenage version of the show who did the deed last year.

PlayboyTV is offering a £100,000 work contract to the first couple to have sex on Big Brother - ironically, the same amount Trojan was charged to screen two models having sex during the commercial break.

Richard Gale, head of European marketing for the adult channel, said: "We are in no doubt that the first sexual exploits seen on Big Brother will be something our viewers will be desperate to see.

"We think this is the year the Big Brother house will come to a climax and we want to be able to replicate the part Channel 4 won't broadcast."