An explicit government advertising campaign will be launched by the Department of Health on Monday as part of a drive to reduce the rates of sexually transmitted diseases.

Radio advertisements will warn of the risk of developing genital warts and spoof Valentine cards will be distributed in clubs, student unions and other young people's social haunts.

One of the cards shows a pink teddy bear with its face twisted in pain and the message "I love you so much it hurts ... when I pee."

Another has a couple in a romantic sunset beach scene with rhyming verse: "Oh Valentine, since you came to me you're always in my thoughts, I'll never forget the night we met and you gave me genital warts."

Adverts will also feature in tabloid newspapers, and radio adverts, to run after 9pm on independent stations, will test the boundaries of taste, even though they have been passed by the radio advertising clearance centre.

One 50-second advertisement asks: "Which of 25 sexually transmitted infections could Cupid bring you tonight? Genital warts ... Yes, this Valentine's, don't forget those three little words, human papilloma virus. Surprise your loved one with cauliflower lumps on your genitals. And warts this? They could spread to your bottom and scrotum. Have them cut off, but they may not leave you for good. It's perfect for incurable romantics - an incurable virus. You can be together for ever."

The campaign is also supported by a sexual health hotline and a new website, www.playingsafely.co.uk.

The latest stage of the £4m "sex lottery" campaign aimed at jolting sexually active 18-30-year-olds out of complacency was justified by Melanie Johnson, the public health minister, yesterday as "targeting those most at risk by using thought-provoking language and direct language".

Ms Johnson is particularly worried by the soaring rates of chlamydia, an infection whose incidence in England increased by 139% in six years to more than 78,000 new cases. As many as one in 10 people may be infected but most will not know it can lead to serious health problems including ectopic pregnancy and infertility.

In the last 10 years, new sexually transmitted infections in England have more than doubled to nearly 1.5m a year. "We have a problem of growing seriousness," said Ms Johnson.

The government is however unlikely to run television campaigns on the issue, despite the famous tombstone HIV/Aids advertisements of the 1980s. Advisers think young people might think them too didactic.