[zoombini]

If you change the lock for one of your own, I cannot see how the council can say that it then becomes thier property?
I'm sure that there must be some law somewhere that says its still your lock.
If you were to fit an expensive new TV Aerial, would the council expect to become the owners of that? providing you put back the original when you leave I dont think they could.

If you were to leave the house without a lock then you would be liable, if however you left it with the current lock in you would not.
So how can they make you liable if you replace the councils lock upon leaving (not that you have any intent on leaving).

I think a bit of council bull is apparent here.

Plastic door barrels are more than £2 now, when was the last time you got one guys? I just tried to find one to replace a plastic door barrel & the only ones I could find still cost me a tenner, B&Q did not have any such lock (if they did I'm sure it would cost more than £2).