have you gone into the criminal justice bill / new age traveller / free festival / spiral tribe / squatter / reclaim the streets / stonhenge stuff yet?
there's a ton of info around on the net , just google some of the phrases above and you'l find a whole history of politics in music in the thatcher era of the late 80s early 90s
http://www.spiral-tribe.org theres so much more just get on the trail and you'l fine it very wel documented
wikipedia , bbc have stuff about it
other googleable phrases could be , liberator djs / bedlam sound system / immersion sound system / free parties / squat parties / wharehouse raves / acid techno
maybe you know al this
maybe not , just trying to help