[smartie]

Another route you might try if you do have problems with the MOD is to get the politicos involved. If you could get your local MP interested (being cynical, lots of them want to be seen as green these days) he/she could put pressure on the relevant MOD Minister, who might also like the publicity. If a Minister tells the civil servants to do it they generally will. The politicos might want to take the credit for the idea, but at least you would get your trees.

One of the key things in big Government Departments is to get to the right person - someone who has authority to act in the area you are interested in. If you don't know who that is Eeyore's friend might be able to help with a name?