"but how did she use the police/army/judiciary to repress their views?"
In practical terms - one of your "certain people/sections/unions," it would seem

http://news.bbc.co.uk/local/sheffield/hi/people_and_places/history/newsid_8217000/8217946.stm

Elsewhere it has been established that part of Thatcher/MacGregor's agenda was to loosen the grip of the Trades Union movement on British industry
Dawn raids on miners homes, the sealing off of entire mining villages with police road blocks, police waving their pay packets at miners struggling to feed their families..... all is part of the history of the miners strike Nigel.
As I said, classic fascism - the state versus the people.
Jim Carroll