Until the late 19th century much of our city space was owned by private landlords. Squares were gated, streets were controlled by turnpikes. The great unwashed, many of whom had been expelled from the countryside by acts of enclosure, were also excluded from desirable parts of town.

Social reformers and democratic movements tore down the barriers, and public space became a right, not a privilege. But social exclusion follows inequality as night follows day, and now, with little public debate, our city centres are again being privatised or semi-privatised. They are being turned by the companies that run them into soulless, cheerless, pasteurised piazzas, in which plastic policemen harry anyone loitering without intent to shop.

Street life in these places is reduced to a trance-world of consumerism, of conformity and atomisation in which nothing unpredictable or disconcerting happens, a world made safe for selling mountains of pointless junk to tranquillised shoppers. Spontaneous gatherings of any other kind – unruly, exuberant, open-ended, oppositional – are banned. Young, homeless and eccentric people are, in the eyes of those upholding this dead-eyed, sanitised version of public order, guilty until proven innocent.

Now this dreary ethos is creeping into places that are not, ostensibly, owned or controlled by corporations. It is enforced less by gates and barriers (though plenty of these are reappearing) than by legal instruments, used to exclude or control the ever widening class of undesirables.

The existing rules are bad enough. Introduced by the 1998 Crime and Disorder Act, antisocial behaviour orders (asbos) have criminalised an apparently endless range of activities, subjecting thousands – mostly young and poor – to bespoke laws. They have been used to enforce a kind of caste prohibition: personalised rules which prevent the untouchables from intruding into the lives of others.

You get an asbo for behaving in a manner deemed by a magistrate as likely to cause harassment, alarm or distress to other people. Under this injunction, the proscribed behaviour becomes a criminal offence. Asbos have been granted which forbid the carrying of condoms by a prostitute, homeless alcoholics from possessing alcohol in a public place, a young man from walking down any road other than his own, children from playing football in the street. They were used to ban peaceful protests against the Olympic clearances.

Inevitably, more than half the people subject to asbos break them. As Liberty says, these injunctions "set the young, vulnerable or mentally ill up to fail", and fast-track them into the criminal justice system. They allow the courts to imprison people for offences which are not otherwise imprisonable. One homeless young man was sentenced to five years in jail for begging: an offence for which no custodial sentence exists. Asbos permit the police and courts to create their own laws and their own penal codes.

All this is about to get much worse. On Wednesday the Antisocial Behaviour, Crime and Policing Bill reaches its report stage (close to the end of the process) in the House of Lords. It is remarkable how little fuss has been made about it, and how little we know of what is about to hit us.

The bill would permit injunctions against anyone of 10 or older who "has engaged or threatens to engage in conduct capable of causing nuisance or annoyance to any person". It would replace asbos with ipnas (injunctions to prevent nuisance and annoyance), which would not only forbid certain forms of behaviour, but also force the recipient to discharge positive obligations. In other words, they can impose a kind of community service order on people who have committed no crime, which could, the law proposes, remain in force for the rest of their lives.

The bill also introduces public space protection orders, which can prevent either everybody or particular kinds of people from doing certain things in certain places. It creates new dispersal powers, which can be used by the police to exclude people from an area (there is no size limit), whether or not they have done anything wrong.

While, as a result of a successful legal challenge, asbos can be granted only if a court is satisfied beyond reasonable doubt that antisocial behaviour took place, ipnas can be granted on the balance of probabilities. Breaching them will not be classed as a criminal offence, but can still carry a custodial sentence: without committing a crime, you can be imprisoned for up to two years. Children, who cannot currently be detained for contempt of court, will be subject to an inspiring new range of punishments for breaking an ipna, including three months in a young offenders' centre.

Lord Macdonald, formerly the director of public prosecutions, points out that "it is difficult to imagine a broader concept than causing 'nuisance' or 'annoyance'". The phrase is apt to catch a vast range of everyday behaviours to an extent that may have serious implications for the rule of law". Protesters, buskers, preachers: all, he argues, could end up with ipnas.

The Home Office minister, Norman Baker, once a defender of civil liberties, now the architect of the most oppressive bill pushed through any recent parliament, claims that the amendments he offered in December will "reassure people that basic liberties will not be affected". But Liberty describes them as "a little bit of window-dressing: nothing substantial has changed."

The new injunctions and the new dispersal orders create a system in which the authorities can prevent anyone from doing more or less anything. But they won't be deployed against anyone. Advertisers, who cause plenty of nuisance and annoyance, have nothing to fear; nor do opera lovers hogging the pavements of Covent Garden. Annoyance and nuisance are what young people cause; they are inflicted by oddballs, the underclass, those who dispute the claims of power.

These laws will be used to stamp out plurality and difference, to douse the exuberance of youth, to pursue children for the crime of being young and together in a public place, to help turn this nation into a money-making monoculture, controlled, homogenised, lifeless, strifeless and bland. For a government which represents the old and the rich, that must sound like paradise.

• This article was amended on 23 January 2014. The original said that an asbo had been granted which prevented "a soup kitchen from giving food to the poor".This has been corrected.

Twitter: @georgemonbiot

A fully referenced version of this article can be found at monbiot.com