DAVID FROST says:
The Ground Game Act 1880 gives every occupier of land the inalienable right to kill hares and rabbits on the land.
You would be an occupier for this purpose if your grazing rights run for more than nine months.
Only the tenant and residents or employees having his written authority may do so and apart from the tenant only one other person may be given permission to use a firearm.
If there are no residents or employees you may pay one person to take ground game on your behalf.
If you wish to shoot rabbits at night you must have the written permission of the holder of the shooting rights.