When it opens this week, Granary Square will be one of the biggest public spaces in Europe – a focal point for the regeneration of King's Cross, a neglected part of London. It will be managed in a private estate of 10 plazas and parkland near the rail hub.makes this clear. "Welcome to King's Cross," it reads. "Please enjoy this private estate considerately."

Over the past decade, large parts of Britain's cities have been redeveloped as privately-owned estates, extending corporate control over some of the country's busiest squares and thoroughfares. These developments are no longer simply enclosed malls like Westfield in White City or business districts like Broadgate in the City of London – they are spaces open to the sky which appear to be entirely public to casual passers-by.

It appears from the scale of the change that privatisation of space is now the standard price of redevelopment. There are privatised public zones across Britain, including Brindleyplace in Birmingham, jointly owned by the property firms Hines and Moorfield, and Liverpool One, owned by the Duke of Westminster's Grosvenor estate. In Exeter, Princesshay is described as a "shopping destination featuring over 60 shops set in a series of interconnecting open streets and squares". The spaces here are owned and run by the property group Land Securities and the Crown Estate, which manages the monarch's property portfolio. Land Securities also owns Gunwharf Quays in Portsmouth, a waterside complex of shops, bars and restaurants. Bishops Square, which includes Spitalfields market, two squares and historic streets in east London, was sold to JP Morgan asset management in 2010.

There are, of course, significant benefits to the redevelopments, though some worry that Britain's landscape is being slowly redefined by private ownership in two ways. As the Occupy protest highlighted, private owners can refuse right of entry to members of the public, closing off swaths of the city.

Critics also warn that these spaces are being designed on a corporate model that favours ornament – and high levels of footfall for retailers – while community spirit and sustainability are not a priority.

Access to some of the best viewing areas for the Queen's diamond jubilee river pageant, including a number of streets on the south bank of the Thames, was restricted to wristband-wearing guests, a ban enforced by private security guards.

Tower bridge and the Millennium bridge, both owned by the City of London, were reserved for invited guests and closed to the public. Members of the public were warned by organisers that the three bridges open to them – Lambeth, Westminster and Blackfriars – would be "extremely crowded".

Occupy activist Naomi Colvin says: "It is a vision of society in which you work and you shop. At times when you are not working or shopping, you may go to restaurants.

"You may possibly go to some officially sanctioned kind of entertainment activity which is sponsored by X but there's no scope for people to do something of their own – to do something spontaneous."

Although it lies within the London borough of Newham and borders Hackney and Tower Hamlets, the Olympic park is not accountable to any of these councils. A quango called the London Legacy Development Corporation is in charge. After the Games, most of the Athletes' Village will be developed by Qatari Diar – the investment arm of the Gulf state – as luxury rental apartments. The outdoor spaces will not be adopted by Newham but managed by their private owners. The council will be responsible for a limited number of "adopted roads".

To the west, about a mile up the Thames from parliament, another new district is being created. Nine Elms, an area bigger than Hyde Park, will be the site of the new US embassy, but it will also host thousands of homes and offices, and the largest fruit and vegetable market in Britain – New Covent Garden Market. There will be a network of squares, footpaths and recreation spaces. The majority of the open space will be in private ownership.

'A new piece of city'

It is common for developers to argue that they are creating new public spaces where none existed before. A spokeswoman for the London Legacy Development Corporation said of the Olympic Park: "It's worth remembering this was industrial, unused, largely inaccessible land before the works started. The land was contaminated with industrial waste, the waterways clogged with abandoned shopping trolleys and car tyres. There was also a network of overhead power lines that prevented any development." It is not a traditional park but "a new piece of city", she added.

The corporation aspires to create 8,000 jobs in the Olympic Park by 2030. It will also be a place to live for thousands. There will be 7,000 homes in five neighbourhoods, 35% of which will be affordable housing. The Athletes' Village development – to be known as East Village after the Games – will include more than 1,300 affordable homes.

There will also be many luxury homes created at the heart of one of the poorest parts of England. On a media tour of the park, a guide spoke of townhouses bordering parkland, with a "similar feel to what you might see in Regent's Park".

Nick Cuff, Wandsworth council's planning chairman, makes a similar case for Nine Elms as opening up "new" space. "The regeneration of Nine Elms is creating vast areas of new open space on the south bank of the Thames," he said in a statement.

"Chief among these will be a new stretch of the Thames riverside path and a linear park running right the way through the district from east to west. There will also be a network of new public squares, roads, footpaths, cycle lanes, outdoor shopping areas and recreation spaces which together will create an active, pedestrian friendly environment for Londoners to enjoy."

Occupy activists challenge this upbeat narrative. When Occupy London seized an empty office block belonging to UBS, on the fringes of the City, a spokesman described it as "a public repossession", reclaiming a symbol of wasted resources.

Colvin cites the empty UBS building as evidence of "an unhealthy trend" of allowing land to go to waste then claiming it must be redeveloped. "This is the pattern, just let things go to waste, knock it down, redevelop it. And then when you redevelop it, the creation of public spaces which are not public often seems to be a part of that."

The loss of public space is not just a threat to street politics; it risks erasing local character in favour of corporate sterility, Colvin argues. Canary Wharf is "totally cultivated, totally deracinated".

Samantha Heath, chief executive of the charity London Sustainibility Exchange, agrees that developers often want redesigned civic spaces to be ornamental and with a high footfall. She said: "If you look at the [private] open spaces – More London, say – its just a massive paved [area] … fountains which are very nice for cooling but don't actually really cool you if there's no shade. It's energy intensive. In terms of upkeep you need to keep cleaning and grouting them out, but biodiversity is poor."

Politicians of all stripes acknowledge the importance of making people feel part of a functioning community. Boris Johnson has spoken of putting "the village back into the city".

At a public meeting last year, the mayor of London said: "It's not a concept that I find people readily grasp but what I want is an atmosphere of trust and neighbourliness and a village atmosphere in parts of our city."

But villages always included commonly owned public land, Heath said. "In the archetypal feudal village there was always that space of common land where everyone had the right to graze their pigs and behave in a sensible way. There wasn't the sense this was the feudal landlord's land. This was common land."

The mayor has published a manifesto for public space, London's Great Outdoors, which accepts there is a "growing trend" towards private management of publicly accessible space. Johnson writes: "Where this type of 'corporatisation' occurs, especially in the larger commercial developments, Londoners can feel themselves excluded from parts of their own city."

In a report last year, the London assembly's planning committee praised privatised spaces such as Mint Street Park, in Southwark, south London, which is now managed by a local steering group. But it highlighted examples of bad practice including a newly created open space at Paddington Basin where "overzealous security guards" often prevent photography.

Based on a sample of planning documents, the committee found boroughs lacked specific policies for dealing with public spaces in private developments. Meanwhile, local authorities under financial pressure are increasingly concerned about the upkeep of existing public land.

Heath said: "The big crisisthat is hitting most open spaces in London over the past 20 years is the revenue cost of maintaining open spaces, and local authorities who've got a lot of open space constantly worry about how they're keeping it up, and how they stop vandals and graffiti, and maintaining good quality in terms of biodiversity.

"They may not want to give it away, but they certainly want to look at innovative ways of funding the upkeep."

Sir Robin Wales, the elected mayor of Newham, accepts his borough could not afford to manage the Olympic Park. "Originally our view was the park should either be a royal park, or maintained by the [City of London] corporation. We know we don't have an income stream."

In the Occupy protest last year, activists targeting financial institutions camped outside St Paul's cathedral because they were legally prevented from entering Paternoster Square, location of the London Stock Exchange and owned by the Mitsubishi Estate Company. The injunction stated: "The protestors have no right to conduct a demonstration or protest on the Square, which is entirely private property."

Broadgate Estates, which owns and manages the 32-acre office and shopping zone set around four squares between Bishopsgate and Liverpool Street, also obtained an injunction last November. A witness statement supporting the application for an injunction stated: "There are no public rights over the common parts. (The gates to the Estate are ritually closed, once a year, to ensure that no such rights can arise by prescription)."

Obstacles to protest

Colvin said: "You probably remember the way Occupy London started, [people] started a Facebook page, saying: 'let's occupy the London Stock Exchange'. I'm not sure the people who started up that Facebook page understood that Paternoster Square was private land until we started getting the first press reports on it saying: have we talked to Mitsubishi, who own Paternoster Square?"

The Paternoster Square management's application for an injunction noted: "The protest is inspired by the 'Arab Spring' movement." But London's protesters had to find their Tahrir Square elsewhere.

Colvin said: "A lot of this was news to us. We became aware ... of different, more security-conscious estates around London. In that first few months, we had different places take out injunctions against us."

Occupy are not the only activists inhabiting a shrinking public space. Living Wage campaigners say they too have faced obstacles to protest. London Citizens, the community organisation behind the campaign, began with hospitals, which are surrounded by public land. The second phase of the campaign focused on banks, which proved far less accessible. Campaigners who gathered outside Canary Wharf blocks to obtain testimony from low-paid workers were swiftly seen and picked up told by security guards: "This is private land".

Neil Jameson, London Citizens' lead organiser said: "There was a lot of understanding, particularly as we were lobbying also for the security staff to be paid a living wage, so there was never any struggle.

"They let us stay but made it very clear that every piece of land on Canary Wharf apart from the 50 yards outside the Jubilee line station [is private]. That's public land and whenever there is a demonstration about anything on Canary Wharf it is on that piece of land – they are directed to a little plot."

The injunctions against protesters have demonstrated the limits of tolerance when public space is in private hands. In the UK's capital, even the most visible emblem of local democracy is in private hands. City Hall and the surrounding pedestrian area on the Thames is owned by More London and run as a "managed estate" with its own private security.

Additional reporting: Joshua Saunders

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