Thanks all. I thought that was the case. Just wasn't sure if there was some 100 year old law with some caveat.
I've spoken with the owner of the flat downstairs who is going to give the tennants a rev and sort it out.
I own the top flat of a terraced house conversion. The tennants below have recently mounted a sky dish directly onto the wall outside my reception room, partially blocking my view.
I know this question has been asked in the past re freehold properties but as this is leashold do I have the rights...