Lellandi trees (planted as a hedge) over 15 foot in height too close to my property

The neighbour (104 or 110 Wentworth Drive) that backs onto the side of my garden (I live at 33 Ingleton Close, CV11 6WB) has several trees (approx 7) planted in a row as a hedge. These trees are over 15 foot in height. I have spoken to the neighbour on two separate occasions and reported that the trees are very near to my property and too high for me to enjoy my garden. He has taken steps to cut the trees back approx 18 months ago, but was adamant he didn't want to trim them to an acceptable level (8 foot would be an ideal as a minimum). I can outstretch my arms from the conservatory we have and touch the trees. I feel this has made a difference to the footings of my conservatory as I can see visible cracking of the plaster inside the conservatory where the tree roots take the moisture from the surrounding soil and make the very clay soil we have contract and therefore move the earth underneath. I feel I have done my best to communicate with this neighbour, but to no real avail, therefore feel I need to get the council involved to take measures. I feel this issue has been in existence for over 5 years now and want to put an end to this issue.