Basically under UK law, you are allowed to take pictures of private property provided you take them from a public place. There are some limitations of privacy concerning publication of the images, but this is of no use to you.
There is a way, if it is persistently taking pictures of you or your property then this can be classed as harassment. Make a formal complaint of harassment to them if this is the case, if they ignore it then make a complaint of harassment to the police.
As I minor point, is the camera clearly on public property, does it overhang a boundary or anything? If so then that would simplify things - just tell the council to bring an axe.
Although I can't find any immediate references to it, if there are children living or regularly visiting your property then there must be some method of using this to limit its operation. It is not unreasonable to have your bathroom window open, and it was there before the camera.
In a time of universal deceit - telling the truth is a revolutionary act. George Orwell
When the debate is lost, slander becomes the tool of the loser. Socrates