Gabion: Will Alsop challenges Norman Foster in London’s East End. 1/3

A few years ago, not too many people cared about Spitalfields market. It was a timewarp place, a wholesale fruit-and-veg market in East London, a concatenation of trucks and mess that gave you an idea of what Covent Garden used to be like before it went all trendy. And then - as with Covent Garden - the market moved out and went somewhere less interesting. And, inevitably, the old market hall followed the Covent Garden pattern and became a fashionable enclave of shops, stalls and bars - though not, thankfully, a tourist haunt.

Now, we are getting the inevitable fall-out of that move. Spitalfields, for centuries London’s first port of call for refugees, from Hugeunots through Jews to Asians, has of late also become a frightfully modish place for well-heeled arts and media types who have snapped up the original Georgian houses in the area, following on from the original conservation vanguard of the 1970s who acquired wrecked houses for a song and successfully prevented the area from being bulldozed.

Today, property values in the best streets have soared. An annual arts festival is held there. The high profile of the area has helped to restore the masterly church of Christchurch by baroque genius Nicholas Hawksmoor. But the looming problem is the presence of the nearby City of London. This exerts pressure to build lucrative office space. For well over a decade, Spitalfields market has been threatened by successive plans for office blocks. The last recession provided a stay of execution - and the developers themselves magnanimously allowed their market hall to be colonized by the new wave of traders - but now, the endgame is approaching. Soon - maybe next month, maybe later - the latest revised designs from architect Lord Foster will be unveiled.

His buildings, whatever form they take, will bring the shining blocks of the City marching into the East End, and will involve the demolition of the newer rear half of the market hall. His clients already have planning permission for this, dating from the early 1990s. But the protestors have a volatile secret weapon. He is the internationally successful architect Will Alsop.