I haven't been online since posting my problem and the thread is now closed so I can't reply! Thank you for the advice even if it did cause problems!

As I said originally he is a really lovely friendly puppy, but he just doesn't seem to take discipline seriously, even from other dogs. Yesterday he was playing with an older bigger dog at the beach who got sick of him and started growling but our pup still didn't back off!

Regarding the biting, I just want to say we have tried 'the bite' with the hand in the neck, pushing away, smack on the top of back leg, shouting ouch, screaming (usually in genuine shock and pain) and 'time-out'.

Everything except time out makes him worse, like he thinks we are playing rough and it is a game. Time out works in that he is outside, but often after coming back in he starts again after a few minutes, like he's forgotten

I might just get some rolled up newspaper and try that, I know my mum does that with her fox terrier.

With regards to the lead, it is impossible to tug or pull it out of his mouth once he's got it. It seems he does it when we slow down a bit, he likes a very fast pace!

We are going to get a metal lead and see if that stops him.

It is possible that I am too soft on him and he doesn't take me seriously. He sits on my lap a lot and I cuddle him quite a bit as well, but he is so lovable and I keep thinking he is only a puppy for a little while. Perhaps I am making things worse, I will try and be firmer with him.

Thanks again to everyone who repled with advice.