Definitely a scam! I get them almost on a daily basis and I've never entered the British Lottery. They're trying to get your banking information etc. to rip you off.

Another one is where they contact you from Nigeria, or one of those countries and tell you that their relative has died and left a huge inheritance for them but they can't access the money (???Why, I don't know) And they want you to send all your banking info. so they can send you a cheque. It's all a scam.

You might want to check your computer for a virus also. If you're receiving those kind of things all the time, you might have a virus on your computer. I would do a complete scan with a virus check.