Susie Rushton: My Hackney feels different somehow

Six months ago, one Saturday morning, I walked out on east London without a backward glance, and on the occasions since that I've found myself back in Old Street or Whitechapel, I've felt like an impostor. East London is clubby like that: you're either in, or you're out.

I don't think there is anyone more committed to the area than the writer Iain Sinclair and his passion for the borough of Hackney, in particular, was the theme of a guided tour I joined at the weekend. Our group must have made quite an odd sight: the headmasterish Sinclair at the front, his artist friends, a rabble of curators and press, and two dogs. On a sunny afternoon, when any sensible Londoner was in the park, we were on a bus – an old red Routemaster with comfy seats and a real string luggage-rack – that zig-zagged from Finsbury Park to London Fields and Cambridge Heath Road.

It felt like a different city. We passed close by a house where I used to live, and I was surprised at how hard it was to recognise my old road. Budget hotel chains, oriental supermarkets, new-build developments have in a matter of months changed once-familiar streets.

Sinclair has written a 600-page book about Hackney, but his commentary lingered on the gradual erasure of its unlovely buildings, and the psychological impact this has on the borough's more sensitive residents.

The tour's ultimate destination was the perimeter of the Olympic Park, which stretches from Stratford to the car-breaking yards of Hackney Wick. It was almost sunset when the writer led us into the car park of an industrial block now inhabited by squatters. "This is the front line," he said, with a smile, and gestured at a high, bright blue fence next to the canal. The residents of Hackney Wick, he explained, had simply awoken one morning to find a partition slicing through their neighbourhood.

The only people who have made any visible response to the arrival of the fence are the graffiti artists: Sinclair pointed out furious alligators and gnashing teeth, painted on walls and bridges, opposite the perimeter. Before it got dark, we climbed up five flights of stairs to the top of an old chocolate factory where young artists can rent studios at cheap rates, an arrangement that will expire as the 2012 deadline draws near.

From up here you can easily see over the divide, and take in the view: dozens of cranes, earth mounds, trucks, no trees or grass, a half-finished stadium – and giant green alligators snapping at the fence.