The message of challenge Team UK is:
• Saving sex for marriage is a positive, realistic and healthy lifestyle.Although the message is not given with an explicitly Christian slant, the volunteers of Challenge Team UK are Christians. You can see Stuart's blog Diary of a WIP (WIP is a reference to his life which, as for all of us, is a "work in progress".) Christians give out food on the streets of our cities and this is a good witness to the imperative of charity for Christians. Teaching young people about saving sex for marriage is also an act of Christian charity.
• Saving sex for marriage is a lifestyle of sexual self-control and respect.
• Anyone can start over again and choose chastity, which basically means saving sex for marriage.
• There can be many negative physical and emotional consequences to teen sexual activity - unplanned pregnancies, sexually transmitted infections and diseases, loss of self-respect, embarrassment, anxiety, regret, etc.
• Saving sex for marriage can bring freedom - from worry about health or pregnancy, to be respected for who you are, to plan your future, to enjoy healthy relationships, and more.
I'm sorry not to have heard of these good young people before. Say a prayer for their excellent work with teenagers.
UPDATE: Rachel in the combox has drawn attention to one important drawback in the material regarding civil unions at this page. Obviously, I would not endorse this in any way.