Overlooked by the yacht clubs and riverside villas, Raven's Ait has long thrived on its status as a playground for a privileged few invited to its tree-lined banks in the middle of the Thames.
In the mid-13th century, the islet hosted the nation's nobility for the signing of a treaty that heralded the Magna Carta. More recently, it was run by a high-end wedding company which posted glossy signs proclaiming: "Welcome to Raven's Ait, the unique island venue."
But for the last eight weeks, this 300m-long fiefdom in the heart of a corner of Britain held up as the epitome of suburban rectitude has lived up to its "unique" billing in a way which has sent the net curtains of Surbiton twitching with unusual vigour.
To the throb of bongo drums, the fluttering of rainbow-coloured "peace" flags and the sound of gin and tonics being choked on in nearby sailing club bars, the island – one of more than 80 on the Thames – has been occupied by a group of squatters intent on reinventing Raven's Ait as an ecological research centre and beacon for alternative living.
Where until last November wedding guests sipped champagne and listened to nuptial speeches, a small commune of up 30 new "caretakers" boosted by up to 150 daily visitors has now set up a permaculture vegetable plot, a solar-powered recording studio and a rotating programme of workshops on subjects from meditative healing to the construction of floating eco-island homes.
Current residents include a Greek scientist working on renewable technologies, a landscape artist and a number of veterans of the Twyford Down and M11 anti-road campaigns in the 1990s. Rarely can stockbroker belt Surrey have been forced to cohabit so closely with climate change activism.
Nick "Revolving", the affable father-of-two and marine engineer who set up the squat on 22 February after noticing that Raven's Ait was unoccupied following the collapse of the wedding company, said: "I was staying with my sister on a houseboat nearby and realised the place was empty and being left in a mess. It was a fantastic opportunity to show what could be done with a low-impact lifestyle on an island that has been common land for centuries.
"At a time when the impacts of climate change are making action an absolute priority we can come in here and harness nature. We already have wind turbines. I'm pleased by our surroundings. This area is built on a way of life that has been seriously questioned by the current economic crisis. We can show a way forward."
Equipped with yellow fluorescent jackets to chaperone visitors and operating a strict "no drink or drugs" rule, the co-ordinators of the project, who occupy the island's small house, two flats and a dormitory, are determined to remain on good terms with their well-heeled neighbours.
All music must stop at 11pm and any new resident must serve two weeks probation before being allowed to stay permanently.
Unfortunately, the overtures have not been entirely reciprocated by some in the suburb which provided the fictional backdrop for the 1970s sitcom, The Good Life, in which Richard Briers and Felicity Kendall outraged their neighbours by swapping their begonias for self-sufficiency and penury with a pig sty.
Such were the intransigent views of Surbiton's real-life Margot and Jerry Ledbetters about installing pigs and a vegetable plot at the time of filming that the BBC was forced to relocate the shooting of the comedy to an adjacent suburb.
It would seem that little has changed.
The Royal Borough of Kingston Upon Thames, which owns the freehold to Raven's Ait, has already obtained an eviction notice and told the islanders they must leave within a period of weeks "so that the island can be used to benefit local taxpayers".
As one gentleman entering the adjacent Thames Sailing Club tetchily put it: "Hampton Court is less than a mile upriver. Most people around here vote Conservative. Do you really think this is the right place for a bunch of hippies to teach yoga and grow carrots?"
But yesterday as the squatters held an open day to explain their aims by ferrying assorted visitors from young families to curious denizens of Kingston on the 100m journey across the river, there were tantalising signs that the Ledbetter Tendency may no longer be in the ascendant.
James Richards, 43, a property lawyer visiting the island, said: "It's a brilliant idea to return this place to some sort of community ownership. The more wind turbines and biomass generators here the better. It could be an example to us all."
Others nodded towards the proud history of non-conformism on another of the Thames' aits or eyots in the shape of Eel Pie Island, occupied by squatters in the 1960s and the venue for concerts by bands from The Rolling Stones to Led Zeppelin to Black Sabbath.
Kingston Council said last week that it will look at a proposal from the nascent community to hand over temporary control of the Raven's Ait to a steering community ranging from eco-activists to the Surbiton Mums Group before setting up a charitable trust to run the island permanently as an environmental education centre.
But the local authority also made it clear that it wants the squatters to comply with the eviction ruling, which the group are appealing against. They insist that Raven's Ait is ancient common land and point to an undertaking by the council in 1989 to secure the site for "educational and recreational use".
All of which means that the current thawing in relations between the islanders and the authorities could be thrown into rapid reverse. The Independent was shown defensive measures that have been built by the squatters to thwart any bailiffs, including a tree house and a concealed tunnel.
Nick, 37, said: "We don't want the council to spend a penny on an expensive eviction and we have said we will leave on an agreed date. But we will only leave when we have an undertaking to develop the island properly rather than handing it over to yet another private enterprise."