The law on hedges or trees that block out light is very difficult to understand and/or enforce. Legislation has been introduced as a result of tall Lleyandi evergreen hedges causing problems, but I'm not sure whether the Council would categorise one evergreen tree as a "hedge". It's obviously best if you can resolve this problem amicably with your neighbour. You are legally entitled to chop off and remove any branches which protrude over your fence boundary into your property but the law requires that you return the chopped off wood to your neighbour (which he probably won't want to happen as he'll then be lumbered with disposing of it. You could try taking a photograph showing how much sun is taken away from your garden and enclose it with a polite note. Offer ready access to your garden for somebody to come and chop off the branches and remove them. If they still refuse to take action, I suggest you then tell him that your enjoyment of your garden is being spoiled to the extent you now feel forced to arrange for all protruding branches to be lopped and returned to him. He can't complain about this. This is the law. He may then decide it's better to have the tree lopped back by a proper tree surgeon and the rubbish taken away rather than being lumbered with a lot of branches cluttering up his garden. Or you could ring your local council for advice. My parents suffered this problem in their garden with a neighbour who refused to have anything done about a very high hedge. In the end they got a tree surgeon in and had all the debris thrown back into the offending garden. If you offer to make a contribution to the cost of getting the tree trimmed, this might make them more receptive as tree lopping is quite an expensive operation.