How awful. 35ft is ridiculous in anyones bookes. Was it a phone or face to face conversation you had with the neighbour Michael?
If you havent done so already ask the neighbour in writing,but in a calm and friendly tone, to cut the trees down to 3m high.
Wait 14 days for a reply. If no action, send another letter, more formal this time explaining that since there is no response or action, you will be seeking support from the local authority.
Write to the local authority asking for support to remove these trees as they are affecting the light and general enjoyment of your property.
Send a copy of this letter to the neighbour.
Good luck. Let us know how all that goes wont you?