Dear all Thank you so much for all your help, being called an idiot certainly helped alot, it meant I had to prove to myself that it could be done. Wire 1 was the supply Wire 2 was for the bathroom Wire 3 was the switch
I could not figur out how to do it without a junction box, so I fitted a junction box, and introduced a 4th wire which was a flex coming out to join with the new light fitting.
Once I had got the junction box it all worked out rather well.
So thank you all again for your help. Cheers Nick