As I have said before - would the military and Police support the government or the people?
If the public kicked off properly, there aren't enough old bill & military (who have shit guns, no boots, and no bullets) to stop it.
Ask the military members on here - I think they would possibly lead!
If we are talking full balls on scenario, they would be daft at the very least if they decided to side with their paymasters.
While they would have the advantage of certain skills (ie, battle planning), you have to bear in mind that....
1. More than a fair number of Joe Public (and most definately "subversive" party leaders) are also capable of strategic planning.
Also add in to the equation that the protecting force will be bound by god knows how many EU & PC regulations regarding how they do the job, while the "subversive" won't give a toss......the outcome is obvious IMO.
2. The physical headcount (government forces vs public).