All trees in Conservation Areas with a diameter of more than 75 mm (at 1.5m above the ground) are automatically protected and you must must submit a formal notification to the Council of any works you intend to carry out to these trees (a Section 211 Notice).
The only way the Council can prevent the works detailed within your formal notification is by notifying you within 6 weeks if its intention is to make a Tree Preservation Order.
If a new order is made the usual provisions apply to trees protected by tree preservation orders. You must not carry out any work during that period without permission. If you do, you could be fined. You may also have to plant a replacement tree.
Permission for works is not required if you want to cut down or work on trees less than 7.5 centimetres in diameter (measured 1.5 metres above the ground), or 10 centimetres if this is to help the growth of other trees.Apply for Tree Work