We've been here before, in about 1640 or so if I recall correctly. But the truth is that what has happened in Faslane has gone far, far beyond an anti- nuclear protest and has provoked a constitutional crisis... or would have done, if anyone in the Commons had cared to notice.
A dictatorship by default in a crisis of monarchical decay appears to be in the offing if this attack is not rebuffed immediately. It may be in the form of a "directorate", a "soft" dictatorship, but it will do the job nonetheless. What happened to Galloway puts me in mind of the case of Matteotti in Italy. 1924, I think it was...

As a matter of urgency, the Commons must declare its sovereignity over the establishment with a view to the founding of a republic. By establishment I mean, Min of Defence, Crown Offices, Lords, Bank of England, and all the rest, oh, not to forget the police. The Commons must summon Supt Bunch to the House and sack him forthwith for usurpation of power.

I doubt whether it will happen. It may also be of interest to note that the police as considering banning any protests in London in early May according to The Times today. Check the article right next to the photo of Galloway...