BRITAIN is in the grip of the biggest skyscraper boom since the 1960s. We’ve already got half a dozen at least the size of the Gherkin about to rise around the City, four more in Canary Wharf, with more coming every month.

In the past few weeks alone a new tower by SOM has been approved in the City, and John Prescott and Ken Livingstone have given the go-ahead for Vauxhall Tower — Broadway Malyan’s 49-storey stump — against the advice of planning inspectors. Now in planning is Europe’s tallest building, Kohn Pedersen Fox’s Bishopsgate Tower, whose lurid helterskelter shape and 1,020ft height mark a new phase in Britain’s relationship with the megabuilding.

This craze is not restricted to the capital. It is the changing face of all British cities. The renaissance of Manchester has been characterised by the sprouting of tens of slightly meek skyscrapers in that shape du jour: the wedge. But half a dozen less reticent successors are rising behind. In Leeds, Liverpool, Birmingham, Cardiff, Swansea, Brighton, Glasgow, Edinburgh, the story is the same.

The trend is echoed around the world. Moscow’s dodgy developers are going hell for leather. Barcelona, Madrid and Paris are all relaxing their height laws. But all fall into the shadow of the space race going on in the East. In won’t be more than a couple of years before the Burj Tower in Dubai, at 2,300ft, dwarfs the 1,667ft of Taipei 101, which itself overtook Petronas Towers in Malaysia only last year.

Ours are tiddlers in comparison. But this hasn’t stopped us from being haunted by the ghosts of the 1960s. What a right load of mingers we got then. A few rose above the dross. But 99 per cent were heavy-handed bores. The 1968 collapse of Ronan Point in East London just provided functional proof for our worries about form. In Britain the skyscraper became the Ozymandian, dystopian archetype, immortalised in J. G. Ballard’s 1975 novel High Rise, in which the modernist block itself turns on its occupants.

Our skyline fell into a coma in 1981, when the City’s 600ft NatWest Tower opened for business. The 1980s might have been boom time but those Conservative years meant a decade renowned for space-guzzling groundscrapers such as Minster Court, not high-rises. The 800ft Canary Wharf in 1991 was the exception, not the rule. It broke its developer and remained alone in the east for a decade, a monument to boom and bust.

But slowly, silently, it gathered neighbours. As Britain’s economy sprang into life again, Canary Wharf finally became the mini-Manhattan of its dreams. Peter Wynne Rees, the director of planning for the City, and the new Mayor of London, Ken Livingstone, began to sidle up to one another (Rees is one of those rare things, a planner who knows about architecture). They reckoned that, with gung-ho Shanghai threatening, the City and the city could survive as a financial centre only if we cut developers some slack. Livingstone started to visit his nippier urban rivals. He invited developers for tea.

Not even the horrors of 9/11 could stem the enthusiasm. It doesn’t take much for a city to forget, especially when there’s a new looker in town to divert attention. The Gherkin proved that skyscrapers didn’t have to be brutes. They could be dishy, friendly, quite clever, almost respectful of the streets below, could add to London-ness, not ruin it. They could be popular, and not just with politicians and money men who have always loved them as easy, obvious graphs of a buoyant economy.

The prestige of the high-rise tower is as strong as ever in the icon age, despite constant worries about oversupply. We’ll even pay a mint to live in them. The 1960s tower block has been on a ten-year makeover — Trellick Tower and the Rotunda in Birmingham are now reinvented for the loft age — and many of Britain’s new towers aren’t shove-’em-in council blocks but high-class flats fed by the rising city-centre populations of our urban renaissance.

Emboldened, developers let rip. Heron Tower was taller than the Gherkin, not exactly ugly, but hardly a looker: after a long public inquiry it was approved. Livingstone wanted it even higher.

The gates were opened. Minerva, 122 Leadenhall Street, the Willis Building, Riverside South were all given the green-light, subject to rules.

Rule number one: look good. Bleeding obvious, but so often forgotten. Rule number two: if you’re a minger, hide behind your neighbours. Few skyscrapers, even good ones, look good alone. Rule number three: don’t just put them anywhere. The City still has stringent rules guarding St Paul’s Cathedral; Livingstone is grouping high-rises in sensible clusters, grooming the skyline. Other cities are following suit with their own skyscraper policies. Edinburgh is even considering extending its World Heritage Site to protect its glorious skyline.

London, and British cities in general, have always been rough-and-tumble places where the developer, not the public, is king. But today’s rush to build big doesn’t mirror the Sixties. These towers are better. We have tougher conservation laws.

The new towers are replacing not cutesy Victoriana but 1960s ugliness; they are inventive and daring.

But there is a Trojan Horse which threatens to up the ante in a way that will affect the future of urban architecture. Renzo Piano’s Shard of Glass on the South Bank is big, really big — 1,000ft — and different: a multi-functional skyscraper layered with offices, apartments, shops and hotels. It’s like those being built in the Far East. But it’s got the nod from John Prescott.

Bishopsgate Tower follows in its hefty wake. If it gets permission (have your say by August 19), the rules of the game will change. London can cope with Gherkin-sized skyscrapers. But when they get above 1,000ft their effect on the street, their sheer bulk, starts changing the fundamentals of the city.

The trouble is, skyscrapers are built more in accordance with the unspoken rules of a kind of gentleman’s club than hard and fast laws. They rely on fair play and the good taste of those in charge of the rulebooks, such as the Commission for Architecture and the Built Environment.

But what happens when the bigger and brasher start barging in? What happens if councils who don’t have an eye for quality (like Livingstone and Rees) let anything through so long as it makes a headline and a fast buck for the greedy and unscrupulous?