Even if the tree itself is not covered by a Tree Preservation Order, it is worth investigating whether the site on which it resides has any legal protection of its own, such as a statutory designation.
For instance, any work involving trees on sites with a designated conservation status, such as a -
- will require prior approval from the relevant agency.
In addition, if the work affects a Scheduled Ancient Monument, advice should be sought from English Heritage, CADW in Wales, Historic Scotland or the Environment and Heritage Service for Northern Ireland.