A little-noticed part of the Anti-Social Behaviour, Crime and Policing Act, passed last October, has given the police a roaming power to bar people from public spaces.

'Dispersal orders' are an extension of previous powers, but the key difference is that they can now be applied in any place, at any time.

Previously, areas had to be declared dispersal zones in advance, after a relatively lengthy consultation process. Now any area can be declared a dispersal zone on the spot: a police officer need only gain authorisation from his or her inspector over the phone.

Once an area has been activated as a 'dispersal zone' - sometimes an area as large as Liverpool city centre - police officers can then bar individuals from the area for 48 hours, or face arrest, followed by hundreds of pounds in fines and court costs, and a criminal conviction.

The only condition for serving a 'Section 34' dispersal notice is that they "suspect" that a person's behaviour "is likely to contribute" to causing "harassment, alarm or distress".

A Manifesto Club briefing document investigated the use of these powers and found that police forces are now declaring dispersal zones before almost any kind of public gathering, including political protests, which poses a direct threat to freedom of speech and assembly.

They were declared in advance of events such as a Christmas lights switch-on in Lancaster city centre, firework displays in Stoke on Trent, and a student night in Warwick, as well as several fairs. In one six-week period, 19 police forces used the new powers 528 times to declare dispersal areas, and dispersed 1,344 individuals.

The new law can be used against almost anyone

Many town and city centres are now weekend dispersal zones, running from Friday until Sunday night. This means that the police can bar someone from the centre of town for the whole weekend if they think that person may cause trouble.

The condition for issuing a dispersal order is so low that it can be used against almost anyone. Those barred from public places include homeless people, a disabled man handing out food for the homeless who was issued with a dispersal notice which barred him from central Brighton, making it a crime for him to re-enter the area, and football supporters who had pulled up by the side of the road in an isolated area.

One of the football supporters later described his experience: "Our treatment was unreal, around 48 of us received Section 34 orders. We simply pulled up on the edge of town, got out of our bus, and were surrounded by police within a minute. We were held there for two hours and given one option - accept the order or be arrested ... There was no trouble at all, the road we were on was remote, there were absolutely no rival fans anywhere near us ... "

In the case of young and homeless people particularly, their sheer presence in public space was commonly cited as "intimidating" or "anti-social". For a homeless person to just sit on a bench - especially with a drink in hand - is often seen as reason enough for criminal sanction.

Many forces said that they brought through orders in response to "begging" or "street drinking", and some said that orders were issued against under 18s who were "congregating" in public spaces.

The law has also ben used to disperse lawful protests, with worrying implications for our democratic freedoms. Merseyside Police have used their powers against political protesters on consecutive weekends - in one case targeting activists who were chatting and deciding which pub to go to for a drink. Police also used the powers to remove protesters against the controversial redevelopment of a Southwark housing estate.

Giving the police free rein

In effect, officers now have powers to act on their hunch that someone is "suspicious" or "up to no good". Police chiefs describe these orders as a "useful tool" and have told officers to issue orders if they "see people who they think may cause a nuisance".

Since officers do not actually possess clairvoyant powers, they do not actually know whether somebody is going to commit an offence, and the result is only to give free rein to hunches and prejudices.

I recently received an FOI response from Cambridgeshire Police detailing some of the dispersal orders issued in a six-week period, showing the flimsy basis on which people can now have their freedom of movement suspended.

One person was issued with an order when they were "seen walking and loitering" along a particular road. Another was "seen to approach and meet up with another male acting in a suspicious manner." A fan outside Peterborough United football ground was "seen to be part of a group gesturing and appearing to swear towards the away fans."

One person issued with a dispersal order was a "male suspected of urinating in a public place, drunk, bumping into members of the public." There were also cases of the orders being used against homeless people, who were barred from an area of town after having been seen committing the offence of begging.

Some police forces seem to be suggesting that merely being present in a public place for any length of time is an illegitimate and questionable activity. One police superintendent said that people would automatically be asked to move on from the dispersal area within Worcester City Centre:

"People are more than welcome to use the pubs, clubs and food outlets in the area. However, once they leave these premises we will politely ask them to move on quickly."

The wide variety of situations included indicates that forces are using these orders almost on a whim: powers are seen as "handy", useful to "nip a situation in the bud" or "stop crimes before they happen".

A fundamental shift in the law

What is entirely absent is the notion - the basis of criminal law for centuries - that powers should only be used against those who have actually committed an offence. No punishment without crime, no crime without a law. This was the basis of common law from the Magna Carta onwards.

Now, however, both police and politicians seem quite happy to enter into the realm of punishment for pre-crime, pseudo-crime or nearly crime. There is punishment for "loitering" or "looking suspicious", or those grievous offences of "bumping into people" or "appearing to swear". Punishment, in some cases, because you look to an officer like the kind of person who might do something.

The barring of individuals from their city centre for a weekend is not seen as a terribly serious measure. Some police forces have dispersal notice cards that they can give out, like leaflets. Dispersal powers are not taken seriously because, ultimately, members of the public are not respected: they are not seen as free men and women, but pins to be pushed around in a pragmatic manner.

This is quite wrong. The great constitutionalist A V Dicey noted that under English Common Law, any restraint of citizens not based on a criminal offence was itself unlawful, and the person could sue the police in the ordinary courts. Every dispersal order is just this: unlawful restraint.

We should stand up for the true law of the land - the principle that we must have committed a crime before the coercive powers of the state can be used against us - against the sham of legal principle which has taken over our statute books.

The report: 'Dispersal notices: the crime of being in a public place' is a Manifesto Club briefing document by Josie Appleton.

Josie Appleton is director of the Manifesto Club, a campaign group for freedom in everyday life.

This article was originally published by openDemocracy under a Creative Commons Attribution-NonCommercial 4.0 International licence.