What do a gherkin, a walkie-talkie, a scalpel, a garden trellis and a can of ham have in common? Is the answer the start to a very muddled joke?  No, Londoners, or anyone who has appeared within twenty miles or thirty thousand feet of the capital in the last ten years and is blessed with vision beyond blindness will, upon witnessing the “evolution” of the capital’s skyline, be aware that the answer is as follows. They are all nicknames for tall buildings of questionable quality.

“How do we responsibly adapt the rich and venerable heart of a globally renowned and ancient city to the 21st century, without compromising the wealth of its heritage and the sanctity of its skyline?” asked the City of London Corporation. “By commissioning 455 skyscrapers large enough to extinguish the sun,” replied Boris. “But they need to be in the shape of things you’d buy at the Tesco Superstore in Brent Cross”, he added.

Something like this conversation must have happened in order for us to end up with the ghastly theme park that now slumps, stretches, wriggles and will presumably soon cartwheel in a swaggering, amorphous tangle from one side of the City to the other. Half of them look like they could, at any moment, get up and run away. If only they would.

Of course there are burgeoning pressures. London is growing, density is rising, but the Green Belt is staying and investors have been investing. And it’s fair to say London is a city whose lifeblood is in its eclecticism. And yes, Foster and Partners’ Gherkin is both a sublime feat of architectural ingenuity and looks like it could be served in a burger. But to use this as a template upon which to remodel London’s financial fulcrum is risible. The Gherkin was not a success because it looks good on a plate but because, back in 2003, there was only one of it, and it therefore held glassy dominion alongside Wren’s elegant and established ecclesiastical footprint.

What does not work is an “if it ain’t broke, churn ‘em out 30-a-year until we run out of relatable domestic nouns to attach to them” approach. This is how London ended up with the self-indulgently corpulent Walkie-talkie, which not only looms hungrily over Aldgate looking for serious architectural critics to devour, but also exemplifies the voracious need to out-perform its neighbours to the point where engineering integrity is overlooked. The south side of the building was angled in such a way as to harness the power of the sun and channel it into melting the streets below. This level of structural myopia is unacceptable, particularly among those gargantuan structures that exist to embody London’s (and indeed Britain’s) immutable international gravitas and prestige.

Recently, as I walked past the most recent addition to “Dubai-on-Thames”, the “Vase”, and appreciated the imagination that must have gone into seeing a vase rather than just a pregnant bulge, I was struck by the insecurity of it all. This high-rise bombardment is, in its absurd, voluptuous versatility, sabotaging any idea of era-defining distinction or hegemony. What meaning can be derived from a heap of projects that are engaged in such naked competition and who seek to literally overshadow their neighbours? This high-rise explosion evokes less a cultural  expression of post-millenium urban innovation than a contorted brawl outside a nightclub. And if the goal is simply to steamroll in “the future”, then planners would do well to remember the timeless adage that nothing ages as fast or as badly.

I like the Gherkin. I like the Shard- ish. And it is fair to say that those goliaths that will ostensibly complete what architect Eric Parry described as “the jigsaw” (as though to some obscure and possibly divine aerial observers, there was some kind of architectural grand-plan all along), are not as willfully curvy as their predecessors. But they are enormous. The Undershaft (or the trellis, near Bishopsgate) will be mere metres shorter than the Shard, and 22 Bishopsgate, another tower under construction, already looks like a girthy chunk of the wall that divides Game of Thrones’ island of Westeros from the army of the dead. These blocks may not yet obscure the odd hallowed view of St Paul’s, which is protected, for now, but they will stomp the identities of existing and recent buildings like the Gherkin and Lloyd’s into the ground.

Perhaps this is the legacy of several unscrupulous decades of rampant architectural optimism – a reaction to the sober monotony of late 20th century buildings such as Canary Wharf. But if this is going to become a consistent response to urban pressures that are unlikely to diminish in the near future, then we need to start thinking more seriously about planning policies that curb an out-of-control desire to throw buildings up in the air, no matter how they look.