Get in touch with the council (streetscene should know the department), if there is a History
of the tree being dangerous then they can demand that it is made safe amongst other reasons.
In England and Wales, local authorities have powers to deal with trees on private property which are on the point of causing damage. A local authority can:-
make the tree safe, if it is on the point of causing damage and are asked to do so by the owner of the land on which the tree stands. The local authority will recover the costs of doing this from the owner
make a tree safe on someone elseís land, if asked to do so by a neighbour whose property is in imminent danger from the tree and the owner of the land on which the tree stands is not known
serve a notice on someone who has a tree which is on the point of causing damage to the property of a neighbour and that neighbour asks the local authority to take action. The owner of the tree must comply with the notice. If they do not, the local authority will do the necessary work and recover the costs from the owner. The owner can appeal to the county court against the notice.
If you want the local authority to take action, you will need to find out which department deals with dangerous trees as this varies from one local authority to another. You can then ask this department to check the condition of the tree.
It is up to the local authority to decide if the tree is on the point of causing damage. If they consider it's not on the point of causing damage, they don't have to take any action.
In Northern Ireland, local councils only have powers to make a dangerous tree on private property safe if it is overhanging a public footpath or road. If a dangerous tree is overhanging a neighbour's property, you will have to try and come to an agreement with the tree's owner. You could also think about going to mediation or, as a last resort, taking legal action against your neighbour." SOURCE