anywhere that legally has music events and alcohol, opens late etc needs a licence, granted by the local council. MK is a sort of US style town with a grid system and all zoned out. the local council (local gov. authority) have got the power to grant or not to grant licences to establishments that want to have music, dancing and serve alcolhol (although these are served by different types of licence), and clubs need to have licences that allow them to stay open late at night. so if a venue breaks the term of the licence, eg theres drug taking at the club (hahaahha), rowdy punters causing problems or soemthing, or complaints from residents about nosie, then the council may not renew a licence.
so if you want to stay legal, you have to go through a fairly tortourous prcess to be able to put on events. of course, back in the heyday of raves, it was all illegal, there was no worries about licensing, but since the criminal justice bill of 1994, which was specifically designed to stop raves, people are generally more inclined to use legal licensed venues, which severely restricts the ability to put on big events generally. sanctuary used to host massive hardcore events (legal tho) like world dance and n.a.s.a back in the day until it closed down, and the council might have got problems with basically having 1000's of kids congregating and getting fucked/having fun.
its worth bearing in mind that i have no idea what im talking about, btu theres a kernel of truth in all that i think.