If you tell your teacher you cut yourself, Is it legal in the UK for them to call/tell my Mum?

[I choose not to display my name ;)]

Okay. I need to explain before I get a load of hate telling me I shouldnt.
So, I'm nearly 13 Years old, And, I cut myself. Not very badly, but still a tiny bit painful.
Yes I have help, Someone who's been in the same situation as me, but worse, is helping me, and she recommends that I see a teacher when we go back to school next week.
Last year (Year 7) I won Netballer of the year at school, I received a Trophy, Jumper ;D and certificate. Even though that was last month, I'm still very proud of myself.
One teacher at school, Teaches me in Netball, and she only joined around May/June time. But she is lovely. She is now my Co-Mentor for year 8!
I was thinking of letting her know, So she could help me, and so my friend doesnt have to do this alone. My friend is going to University now, So i wont see her ;( But i can stay in contact over the phone, Facebook and Twitter, etc etc. But, Im so afraid of telling my Teacher incase she calls home or tells my Mum at a parents evening or something. I thought it was confidential but some still say that she can? Help Please?
Sorry, What if i ask her not to call home?

[Zombie Killer]

didn't read but the simple answer is yes
they are still your legal guardian and have the right to be informed untill 16 or 18 whatever age it is XD

[Pete]

Yes, it's not like the doctors (who can anyway, as your under 18)

[Adam]

Its a teacher, not a psychiatrist. She can and probably will tell you mom.

[Desdemona]

Yes, because you are under immediate danger. They may give you the chance to tell your mum yourself but if you don't, they will tell.
You need help. And no, another past self harmer is not help (no offence). You need help as in professional help like counselling. I am sure your school will have a free counselling service that you can use and trust me, it will help you a lot. By the way, a counsellor will also tell your mother that you have been self harming.
It's best that you just tell her. What are you scared of? I am sure she will try and help you with whatever happens to you because she is your parent. That is her job. And then you can get on with getting some actual help.

[Beastie]

Sorry, this is not going to be what you want to hear. Good that you've got help, at least, but no matter how nice your teacher is she's under no obligation to keep anything you tell her to herself, especially if it's something like this. Teachers do not work under any sort of confidentiality rules. If they think your parents need to know something it is up to their conscience whether to tell them or not.

However, I would say that if it's under the context of asking for her help she's more likely to advise you to tell your parents rather than tell them herself. Equally she would also likely take your wishes into account. The only way you'll know any of these things for certain about her is if you tell her.

[jimbo]

What you need to understand is that the school and the teachers are loco parentis when you are in school. What that means is they have the power to act as your parents would reasonable act in any situation. So yes they have the power and the right to inform your parents.