“Covert Human Intelligence” in Brixton, 20 October 1990.

Like thousands of socialists, I spent the 31st March 1990 marching through London in protest at the Poll Tax introduced by the Thatcher Government. It began with a carnival atmosphere and ended up with police horses charging through Trafalgar Square, seemingly oblivious to the bodies being trampled underneath. Me, I ran from the scene, with my then girlfriend, up towards the relative safety of Kings Cross, where I was staying at my sisters. But that’s not the story I want to tell.

That day, over three hundred activists and protesters were arrested on the day for their part in that so-called “riot”. Subsequent footage showed that in many cases, it was the police who attacked marchers, before any retaliatory violence from those gathered in Trafalgar Square. Many of those arrested were taken to Brixton Prison while awaiting trial.

In October of that year, over 20,000 protestors gathered in Brockwell Park and marched up Brixton Hill to the prison, loudly demanding the release of the Trafalgar Square prisoners, but with little hint of the trouble to come. I was part of the group that arrived first at HMP Brixton and I found myself right up against the police. What I saw then has stuck in my mind and informed my view of the policing of demonstrations and the role of covert operations. There’s something about seeing things for yourself, up close.

What I saw was a non-descript van pull up alongside the police and out of it poured 8-10 men, in normal clothes – denims and parka jackets, who then blended into the crowd. I saw with my own eyes that they were clearly carrying things – weapons, what looked like stones, bricks and bottles. The police seemingly did nothing to intercept this group and within seconds, they had started to throw these missiles into the crowd of 30 or so police who were gathered outside the prison. I was convinced at the time that these were provocateurs and nothing has convinced me otherwise since.

Scuffles broke out, the police charged and used their batons to hit protestors at random. After some push and pull, the existing police lines were joined by more police coming from vans stationed at the top of the hill. Once again, I found myself having to run. I sprinted down the hill, aiming for the tube. I was hit by a police baton – not hard, but enough to knock me off balance and into a street stall. I picked myself up and tried to apologise to the stall owner. I ran and ran until I was lost, but out of the area.

Later, I watched the news describing another Poll Tax demonstration ending in violence and another contextless series of images showing protestors fighting with the police. Even at that age – I was 18 – I knew this went on, that agent provocateurs peppered organisations, campaigns and demos, but it’s one thing knowing in theory, it’s another seeing it in practice. And of course, watching the final “product” for the news media is a salutary experience.

I was thinking of this incident while the debate was raging about the Covert Human Intelligence Sources (CHIS) Bill this week. I know this is small beer compared to the vast numbers of crimes, abuses and injustices that have been committed by the state, or with the collusion of state agencies, in the name of security over the last half decade, both on the British mainland and the island of Ireland, but the sheer mundanity of those men, piling out of that van to create a riot that may never have happened, is symbolic of something deeper, for me.

When you think of the murder of Pat Finucane and the many people waiting for justice in Norther Ireland, the carefully orchestrated attacks on miners at Orgreave, the cover-ups over Hillsborough and countless historical child abuses in detention centres such as Medomsley on my doorstep here in Durham, what is missing is two-fold: first, any morality. Nothing, and I mean nothing, is beyond bounds. Secondly, accountability – and by that I don’t mean self-policing, but genuine, open, democratic accountability, with human rights and justice at its heart. In my view, that should have been the subject of the debate this week, not optics.