Carrying out some more research on the history of the Stop the City demonstrations, I’ve come across two brief video news reports from Thames news (uploaded from the Thames TV archive) from the third (and so-called ‘secret’) Stop the City, held on 31 May 1984.
The first is a very brief (27s) compilation of raw footage from the day (from which the news editors would have selected content).
The second is a brief (1m09s) edited report prepared for transmission (during the local London news slot that evening), complete with editorial commentary (and featuring a few seconds of footage from the second Stop the City held on 29 March 1984).
The police made hundreds of arrests at the third Stop the City in an attempt to smother the demonstration. Note that even the Thames TV crew gets threatened with being nicked.