Who decides it

You make enforcement appeals to the First Secretary of State at the Office of the Deputy Prime Minister. Almost all appeals will be decided by Planning Inspectors. The Secretary of State can decide any enforcement appeal, but does so in less than 2% of cases, usually if there are issues which affect more than just the local area. He won't decide your appeal just because you have asked for this. But if he does, The Planning Inspectorate will tell you why.