It could have been worse: at least the police didn't try to kettle half a million people. But as footage obtained by the Guardian from the great march on Saturday shows, the glorious tradition of impartial policing and respect for peaceful protest remain undimmed. The film shows senior police officers assuring members of UK Uncut who had peacefully occupied Fortnum & Mason that they would not be confused with the rioters outside, and would be allowed to go home if they left the store. They did so, and were penned, handcuffed, thrown into vans, dumped in police cells and, in some cases, left there for 24 hours.

Isn't all that supposed to have stopped? Haven't we entered a new era of freedom in which the government, as it has long promised, now defends "the hard-won liberties that we in Britain hold so dear"? No.

In May 2010, after becoming deputy prime minister, Nick Clegg pledged that the government would "repeal all of the intrusive and unnecessary laws that inhibit your freedom" and "remove limits on the rights to peaceful protest." The Queen's speech firmed up the commitment by promising "the restoration of rights to non-violent protest". So how did this grand vision become the limp rag of a bill now before parliament?

The Protection of Freedoms Bill, currently in committee, is a change for the better. It limits the period of detention without charge for terrorist suspects; reforms the measures that allow police to stop and search anyone they please; regulates CCTV and council snooping; and prevents the police from holding the DNA records of innocent people indefinitely.

All this is welcome, but it scarcely grazes the mountain of repressive legislation that has piled up since Margaret Thatcher was in power. It doesn't even acknowledge the intrusive and unnecessary laws in the 1986 Public Order Act, the 1992 Trade Union Act, the 1994 Criminal Justice Act, the 1997 Protection from Harassment Act, the 2003 Antisocial Behaviour Act, the 2004 Civil Contingencies Act and the 2005 Serious Organised Crime and Police Act. In fact the new bill contains not a single clause restoring rights to non-violent protest.

Here are just two of the dozens of repressive measures these acts contain, which have been used repeatedly to criminalise peaceful protest. Neither, as far as I can see, has ever been mentioned by Clegg, Cameron or their ministers.

When the Protection from Harassment Act was being debated, campaigners warned that a bill whose ostensible purpose was to protect women from stalkers was so loosely drafted that it could be used by the police however they wished. The warnings were ignored, and the first three people arrested under the act were not stalkers but peaceful protesters. The police used the law, among many such instances, against protesters outside the US intelligence base at Menwith Hill, who were deemed to have harassed American servicemen by holding up a placard reading "George W Bush? Oh dear!"; and against a protester in Hull, on the grounds that he had been "staring at a building". Notoriously, the act was used to obtain an injunction against villagers in Oxfordshire, protesting against a plan by RWE npower to turn their beautiful lake into a fly ash dump. If they went anywhere near the lake, they would be prosecuted for harassing the burly men guarding the site.

But even that did not go far enough for Tony Blair's illiberal government. Buried in the Serious Organised Crime and Police Act was a clause redrafting the 1997 act specifically to catch protesters. Now if you seek "to persuade any person … not to do something that he is entitled or required to do" or "to do something that he is not under any obligation to do" you can be nicked for harassment. This, of course, is the purpose of most protest: to try to persuade people to change the way they act. Hundreds of peaceful demonstrators have now been stigmatised as stalkers.

Still more pernicious, because the penalties are so severe, are the measures contained in sections 145-149 of the same Serious Organised Crime and Police Act. These are aimed at animal rights protesters, which might be why you have heard so little about them. Because some have used violence, intimidation and arson, hardly anyone seems prepared to defend the far greater number who support the same causes peacefully. The act prohibits "interference with contractual relationships so as to harm animal research organisations". The definition of harm includes causing "loss or damage of any description".

If, for example, you were to send a newspaper article about how one of these businesses treats its animals to a client or a shareholder, you'd be in danger of prosecution under the act. This would be bad enough. But police and prosecutors have cast the net even wider and made the law even vaguer by prefacing it with "conspiracy to".

This was the charge on which a young man called Sean Kirtley was convicted in 2008. He had not intimidated or threatened anyone, or even interfered in a contractual relationship: he had merely updated a website with details about authorised and peaceful protests. Because some of the people who attended these protests used abusive language, and because this language was classified by the Crown Prosecution Service as an attempt to interfere in contractual relationships, Kirtley was alleged to have conspired in the commissioning of an offence. He was sentenced to four and a half years. He was acquitted on appeal, but not before he had served 16 months.

If the government was serious about repealing "all of the intrusive and unnecessary laws that inhibit our freedom", would it not have begun with measures like this? Instead it has published a bill that, it initially promised, would allow "members of the public to protest peacefully without fear of being criminalised", but makes not a single move towards this end.

I don't believe Clegg's claim, which seems to have gulled the usually sceptical Observer journalist Henry Porter, that this act is the beginning, not the end, of the coalition's reforms; and that, in Porter's words, "there may even be a great repeal act down the road that would look at some of the laws not addressed in this bill". Perhaps he is unaware that the original title of the current legislation was the freedom (great repeal) bill.

This legislation shows every sign of having been stopped and searched, fingerprinted and stripped of any content that might have rebalanced the relationship between people and power. Laws like those I have mentioned were introduced at the behest of lobbyists, to stifle peaceful public objections to the dangerous, cruel or destructive practices of corporations. Why should this government wish to repeal them?

• A fully referenced version of this story can be found on George Monbiot's website