All light to garden blocked by a tree

[Huskyman]

Hi,

I am after a little help here with a problem neighbour who has a garden that looks like something off stig of the dump and a stupid 55ft evergreen tree in their garden. Last load of hassle with them involved getting a toilet removed from the garden....
This tree takes away a lot of light into the garden and poses a risk to my house. What are my options?

Any help greatly appreciated.