Pub marquee? how far from house is allowed?

Please help. I have a marquee which is only 10 meters away from my house and 2 feet away from my boundary fence. the pub uses it for live music/social events. The landlord never had permission and has now put in a planning application as he was found out. Does anyone know the law on proximity to a property? My house backs on to a pub garden however there is a big difference between noise from a pub garden and live music. There is also significant visual impact on my garden.