You could declare yourself to be a conscientious objector and see how it goes.
On the other hand, you could always informally ask the question of the 'system', explain your position and ask if you can apply for release - they can only say; 'No'. At present there is a considerable amount of sympathy and pragmatism about the situation people like you are in and I believe an 'upfront' approach will do you no harm.
Old Duffer