If you're touching trees please be certain that they are not covered by a Tree Preservation Order [TPO].
Fines can be up to £20,000 per tree, especially if unauthorised work results in death of a tree.
Your local Council will have records, some records are available online via the Council's website, which is usually www.[name of council].gov.uk
But as everyone else has stated you do have a right to cut overhanging bushes/trees.