a turf war
1. An ongoing fight among factions, often criminal ones, attempting to control a particular territory (i.e. their "turf"). The neighborhood has been torn apart by the turf war between the two gangs.
2. By extension, a dispute or hostile environment among persons or factions competing for a particular position, or influence in a particular area. The school newspaper has become the scene of a turf war among several ambitious students who all want to add "editor" to their college applications. The electoral map has become nothing more than a diagram of the turf war between the two parties.
a ˈturf war(informal) an argument or a dispute about who owns or controls an area: Street violence has escalated as a result of a turf war between rival neighbourhood gangs. ♢ Turf wars are inevitable when two departments are merged.
In informal language, your turf is the place where you live and/or work, especially when you think of it as your own.