It was something that I haven't really seen en masse before. It was something that some people had written off. They said was a bit old hat, doomed to a slow, dwindling death, if it even really existed. It was the working class. Not the working class in the shitty, nostalgic, culturally regressive sense that people invoke, not the deus ex machina mobilised to berate black people and gays for being too assertive of their legitimate rights. It was the working class as an agent of its own interests; it was a class for itself. It was the labour movement, every bit the multicultural entity that Cameron reviles. And that movement, comprising several millions of people, having lain dormant for years, is now looking decidedly up for a fight. If you're a socialist in one of those workplaces on Monday morning, you should have an easier job arguing for militant strike action now, because people now know what they could not be sure of before: that we are many, and they are few.

Before we go any further, a digression. Can I please make an urgent appeal on behalf of sense and dignity for people to stop repeating the idiotic journalistic cliche that a minority of 'hardliners' (or worse, 'violent extremists') spoiled things for everyone else. So much work, you hear them say, so much time spent building up a great day, and these wreckers - yes, wreckers! - have to come and ruin it. Certainly, if all that matters is having a fun day out, giving a good impression in front of the media, the police and the politicians, and 'raising awareness', then I can see the logic. But, quite apart from the fact that people don't necessarily freak out and change their perspective on public services just because a few windows have been broken and paintballs thrown, that is not all that matters. A big march like this a wonderful, confidence-giving, life-breathing event. It helps give definition to the forces, from the left and the labour movement, who are prepared to resist the austerity project. It gives those involved a sense of their potential power. And hopefully it will lead to strike action to defend jobs and services, as Mark Serwotka, Len McCluskey and Billy Hayes promised from the platform.

Yet, what is strike action but a highly orchestrated and strategically situated form of disruption? And is that not what those who occupied Fortnum & Mason's, the most pretentious shop in London with the possible exception of Harrods, and paintballed the usual UK Uncut targets, did today? Isn't the whole intention to normal commerce and governance impossible, to make life difficult until they stop their attacks on us? Surely, the only possible basis for criticising this from an anti-cuts point of view is tactical? If it harms the movement, then there's a case for having this out within the movement. If, on the other hand, it does not harm the movement, then the real wreckers are those dispensing pithy denunciations according to script. Let's also drop the idea that this was done by nutters in balaclavas and face masks. The people involved were a mixture of activists from a variety of political backgrounds, engaging in a serious form of disruptive protest. There were trade unionists outside Fortnum & Mason's cheering them on, and I wouldn't be surprised if there were a few inside as well. Effective protest will always depend on a minority who are willing to risk arrest, or state violence, in order to throw a spanner in the works of unjust policies. Ed Miliband, speaking today, made his usual bland plea for 'peaceful' (meaning legal, parliamentarist) protest, while also situating this movement in the history of suffragism, civil rights and anti-apartheid struggles. Such revisionism does us no favours. All of those struggles were won by people who broke the law, and who devised strategies for breaking the law.

So, that said, those who have tried to argue for an anti-cuts strategy that excludes Labour have a little bit less credibility today. It was actually vital, not only that this was organised by the TUC, but that the Labour Party mobilised for it, and that their leader felt compelled to make an appearance. The labour bureaucracy can turn people out when it wants to, and today it turned out half a million by the reckoning of the police, the organisers and The Guardian newspaper - possibly it was bigger, but there's no need to haggle. Not only was the demonstration huge, but the crowds present represented an extraordinary depth and breadth of people from every segment of the working class - it was a very large, but concentrated manifestation of the labour movement as it exists in this country.

It has become a cliche, but it remains important to say, that among the women's groups, Labourites, socialists, Greens, anarchists and unaligned leftists, were people who don't usually do demonstrations. I saw council workers, nurses, librarians, bin men, firefighters, railway workers, civil servants, and teachers. Each of the sixteen trade union contingents were big, some enormous. Whole workplaces came out for this. Communities mobilised. Over 800 coaches were booked, as were more than a dozen trains. Thousands and thousands came in by scheduled trains and buses, and many of them could be seen wandering around in clusters through the centre's unexpectedly pedestrianised streets well into the evening - wherever I went, and I did take a long walk, a group of protesters with union flags and placards would suddenly appear, and just as suddenly scarper. Beyond the congregation zones, both official and ad hoc, the cafes, restaurants, coffee shops, pubs, and trusted purveyors of the "junior spesh" could be seen packed with FBU uniforms, Unison flags, NASUWT t-shirts, and so on.

Of note is who the crowds in Hyde Park were attuned to, and who they were not. Ed Miliband's speech was, as I've mentioned, weak tea. He was cheered politely, heckled a little, booed by some. His elevating rhetoric almost always falls flat, and the detail of his policy don't inspire - a turnout like this, an historic day like this, and he still has to keep to the tired old policy nostrums. Responsible cuts, yes, but the Tories are going too far. Cut the deficit, but tax bankers' bonuses. And so on. However, unlike Blair, Ed Miliband is not hated by, and doesn't hate, the labour movement. He is not embarrassed to be seen at protests, or be around working class people. And he will have a lot to think about after today - because every sign is that neither the trade union bureaucracy nor the Labour leadership expected anything like this turnout. Christ, until yesterday, the TUC were still talking about expecting 100,000 people. On the other hand, the more militant speakers such as Mark Serwotka were received with glee, particularly when the latter said: "imagine what a difference it would make if we didn't only march together but took strike action together." You may say he's a dreamer. But today we have seen that he's not the only one.

A word about Trafalgar Square. As planned, hundreds - maybe at one stage thousands, I've heard different reports - of people gathered in the square for a bit of Rabelaisian carnival. Every eyewitness report has described it as a party, a rave, pungent with the smell of home grown, but with little prospect of it turning into a big deal. At least it was until riot police attacked it, batoning people and roughing them up. They turned a peaceful gathering into a frightened and bloodied huddle, kettled in a small space. They did not break windows, occupy buildings or paintball facades: they cracked skulls. Having waited all day, and maintained a relatively light touch as long as the official TUC march was going on (this is important - they probably don't particularly want to sour relations with the trade union bureaucracy), they found their opportunity at nightfall by attacking a very small and defenceless crowd of ravers. As they have done on previous occasions, they started a fight and then took the ensuing melee as an excuse to kettle their victims. Why would they do this?

You may as well ask why they would assault Jody Macintyre, put Alfie Meadows in hospital, punch a fifteen year old boy, and rough up teenage girls. It is because it is their job to contain threats to 'public order', and they see violence and intimidation against selected groups of identified 'troublemakers' and 'ringleaders' as the most effective means of doing so. History would suggest that they are not wrong. That's one reason why the people who suffer from police violence and harrassment need to our solidarity. It's also why it is vitally important not to fall into the knee-jerk, at best disproportionate, denunciations of 'violence' against property. Because in doing so, you corroborate the police's narrative and alibi. You displace the proper focus on far more serious and potentially lethal violence inflicted by people who are armed and trained in its application - I don't know how bad things got tonight, but they are going to kill someone one day if things continue in this direction. And you thus assist the weakening and intimidation of your movement. Earlier today, I was listening to a policeman complain to a member of the public that people confuse the police with the government, and forget they're public sector workers. I thought, but did not say, that it's easy to forget when the police spend all their time attacking the government's opponents with big sticks. On which note, this is doing the rounds on Twitter: "Unconfirmed reports that forces loyal to Cameron are attacking rebels in Trafalgar square."