I soon grasped the themes of the march, and I thought I would help out by shouting some fitting slogans: such as "bring back badger baiting", "back to the Middle Ages" and "feudalism now!" To my astonishment, far from applauding my sentiments, my fellow marchers first started jostling me, then requested an officer of the law to apprehend me. This he duly did, and cautioned me under section 5 of the 1986 Public Order Act. The act, the policeman told me, says that "anyone using words or signs likely to cause harassment, alarm or distress to any other may be guilty of an offence".

I asked the policeman whether I would be committing an offence if the slogans I had been shouting had met with the approval of the crowd. He told me I would not. So the legality of my actions, I asked, depends on the political content of what I am saying? "In this case, sir, yes".

A few months ago I argued that our legal system was built on a pre-democratic framework. Since then, however, I have come across two cases of peaceful protesters being arrested or cautioned under the Justices of the Peace Act. This progressive measure was passed in 1361: it predates, in other words, not only democracy, but also parliament. Our legal system was established by a handful of propertied people, to defend them from the objections of those they had dispossessed. It has been used to suppress public participation ever since.

But now, thanks to a series of spectacular cases, Britain's feudal law is on the verge of falling apart. Last week, a jury decided that 28 Greenpeace activists had "lawful excuse" to destroy a field of GM maize. On the same day, a Manchester jury failed to reach a verdict in the case of two women who had partly destroyed a nuclear submarine. In October last year, a sheriff instructed the jury in Greenock court to acquit three women who had thrown all the Trident laboratory's computer equipment into Loch Goil. Having heard that Trident's 100-kiloton warheads could not be used selectively, but would inevitably kill millions of non-combatants if they were deployed, she explained that the women "were justified in thinking" that Trident "is an infringement of international and customary law" and that they had an "obligation in terms of international law to do whatever they could to stop the deployment and use of nuclear weapons in situations which could be construed as a threat".

Tomorrow, the legal implications of this remarkable judgment will be examined by the high court. The three women will argue that the new Human Rights Act will render the sheriff's judgment unchallengeable: Britain's nuclear programme has been declared illegal, and there is nothing that either the judiciary or the government can do about it. Though a complete absence of press coverage south of the border might suggest otherwise, this is surely one of the most significant legal cases ever to be heard in the British courts.

As the Human Rights Act looms into view, the government is beginning to panic. Concerned that juries are using their moral judgment to interpret the law, it seems to be doing all it can to shore up Britain's oppressive legal system. Protesters arrested for destroying a GM crop in Dorset this summer complain about what they perceive as overt political interference in the judicial process. While they were to have been tried for criminal damage, which would have brought them before a jury, the crown prosecution service has reduced the charges to aggravated trespass, which will be heard in a magistrates' court. The defendants are pressing for more serious charges, while the prosecution is arguing for leniency.

Jack Straw's attempts to limit trial by jury, which the Lords will start re-examining this week, are beginning to look less like a plan to save money and more like an effort to keep sensitive cases out of the hands of ordinary men and women, who might be moved to agree with the legal arguments raised against the excessive powers of the state and the corporations. This is not, after all, how the legal system is supposed to work.

But these are desperate, rearguard actions to defend a system which is becoming ever less capable of resisting democratic challenges. The next few months could, as a result, prove to be among the most exciting periods ever in British politics, as the weight of the law is turned against the very systems it was established to defend. Thanks to the challenges presented by a tiny number of courageous people, Britain may never be the same again.

© Guardian Newspapers Limited 2000

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