In reply to Removed User:
Most top ropes I come across at walls seem static, really not suitable for a lead fall.
To the best of my knowledge, no wall in the UK will allow you to use their ropes for leading. You have to supply your own.
Most walls I've been to have separate lines for leading and top roping, but some do combine them, or they're next to each other. Leeds wall and Craggy comes to mind. Also The Edge has a few routes next to each other plus on some top rope routes, there are bolts so you can lead and place your own quick draws.
Leeds wall also has some top rope routes with eyes that you can put your own quickdraws in. In all these walls, you're supposed to leave the top rope in situ, or just move to one side. There's no way you are allowed to pull the rope down then lead using it. Actually in most walls I know of it would be dangerous as the top ropes are often cut to size, so you'd be in danger of the rope running out if you tried tying in (I do know of one broken back at one wall from some idiot who tried this).