A snapshot of the 26 March demo
1815: I've just left Trafalgar Square, where about 200 people are holding an impromptu rave, with a minuscule number of police present to notice the thick waft of sensimilia.
At Fortnum and Mason the demonstrators who took it over are trying to get out, texting me to point out the difference between themselves and the "black block". This latter, about 500 anarchists with black and red flags, systematically threw paintbombs, thunderflashes and flares, trashing a few shops and banks etc, causing mayhem around central London all day, and presumably into the night.
But the massive fact of today was a very large demo of trade unionists and their supporters. I estimate upwards of 250,000. Probably less than half a million but certainly bigger than the Poll Tax demo of 1990, which I witnessed.
The demographics were interesting. Unison - a union which has a reputation in the trade union movement for passivity - had mobilised very large numbers of council workers, health workers and others: many from Scotland and Wales; many from the north of England. Unite likewise, and the PCS seemed capable of mobilising very large numbers.
What this means, to be absolutely clear, is people who have never been on a demo in their lives and in no way count themselves to be political.
I also saw many small self-selected groups not mobilised by unions: family groups, school groups, speech therapy groups.
My guess is that though this is the "labour movement", a number of those marching would have voted Libdem also.
The sheer size and social depth of the demo is what all political strategists will now have to sit down and think about. I'm still thinking about it myself, but recording its size is important: the anti-war demo was bigger - maybe 1m plus - but this was certainly the biggest and most representative demo for 25 years.
At the rally Ed Miliband was heckled by a few, when he said he supported some of the cuts that are coming: Mark Serwotka, the PCS leader, not only called for no cuts at all but fired the crowd up with a call for co-ordinated strike action.
I got a sense that the labour and trade union movement slightly stunned itself with its ability mobilise so many people on the streets. That with Ed Miliband they now have a leader who they don't hate, but in turn Mr Miliband faces a challenge of what to do about this movement.
I picked up a bit of scepticism about him from the protesters; meanwhile his handlers will be pondering the problem of how "associated" he wants to be with the biggest labour protest for 20 years, because most people on the demo would be a little way to the left of the ideas Mr Miliband claims to espouse.
The big takeaway from today is that the trade union movement - though dominated by the public sector - is certainly a force to be reckoned with: what it chooses to do now will be interesting because Miliband's strategists certainly want nothing to do with the mass, co-ordinated strike movement advocated by Serwotka, Len McCluskey etc.
We tend to forget, because we obsess about political parties, that in organisational terms the unions are much bigger than the Labour Party itself. Indeed the Labour Party branch banners I saw were often carried by a few, oldish, colourfully dressed people, whereas unionists tended to be younger and very "branded" by their professions or unions, as with the Unison Filipino Nurses, the FBU etc.
Another note: we tend to think of the public sector unions as white collar or from the service industries but this was not true of today: there were many tens of thousands of manual workers in their bibs, hi-vis uniforms etc. I met binmen from Southhampton furious that they pay is being cut; and of course the Firefighters, designated "stewards" in order to deter the anarchists from coming anywhere near the demo.
At present the sporadic violence around Piccadilly is dominating the headlines. The three groups are getting coverage in inverse proportion to their importance: the anarchists with their thunderflash thowing (I've been close to this stuff all day and it is, though dangerous, fairly ritualistic); the UKUncut groups (a couple of thousand) which have managed to shut down many branches of Vodafone, Boots, various banks and Top Shop with largely nonviolent direct action; and 300,000 people who demonstrated completely peacefully, enduring for many four to five hours of marching and standing.
This passive but fairly angry mass are the people that pose the biggest political problem both for the government and the opposition; because when you can mobilise more or less your entire workplace - be it a special school, a speech therapy centr, a refuse depot, an engineering shop or a fire station - to go on a march, then "something is up".
I should add that, from what I saw, the policing was up until nightfall deliberately restrained. No kettling attempts, no baton charges even when attacked with missiles, few arrests and injuries. This must have been a high-level decision - though of course each contingent of anarchists is followed by forward intelligence teams with cameras and notebooks: for several hours a large group of masked anarchists were allowed to march around, smashing various storefronts.
It now seems like this is changing, and escalating, from the live coverage by my News Channel colleagues, which shows the Fortum & Mason invaders being arrested. But I am now off the demo and watching it on TV.
More follows, including on Newsnight, Monday.