England is now the second most crowded country in the European Union, after Malta. It has, for the first time, inched past the Netherlands, with 402.1 people per square kilometre, compared with the Dutch 398.5. This statistic coincides with a rise in net migration, partly caused by a decline in outward emigration. Some have already been quick to link the two.

Overcrowding, class, immigration and race have long been linked in certain quarters. From the apocalyptic 18th century predictions of Malthus through the cannibal megalopolis of the film Soylent Green to the "demographic threat" in Israel-Palestine, the prospect of a teeming mass of inferior folk causing mayhem and starvation, or simply outnumbering "us", has been a persistent obsession.

But if the EU report is given more than a cursory glance, it is easily seen that the apparently alarming statistic is actually about population density, not immigration, "over" crowding or "over" population – nor even the population density of the UK. England might have a density of 402.1 per square km, but the UK as a whole is well below the Netherlands and Belgium at 256.3, roughly the same level as Germany. Scotland and Wales are far below either, with Scotland's level of 70.9 placing it lower than Slovenia, Bulgaria, Romania. So what this is really about is concentration of population in very particular places and underpopulation elsewhere. A response to that doesn't necessitate draconian immigration caps, but rather something terribly unfashionable – town planning.

Densely populated areas are not necessarily slums. Among the densest places in the UK are Mayfair and Pimlico, or the west ends of Glasgow and Edinburgh. With their expensive stucco squares and sandstone tenements, these places are by no means dystopian. Given their extreme desirability, an extremely high population density is clearly not so alarming.

Architects and planners, disenfranchised by the suburban non-plan of Thatcherism, spent the 80s and 90s agitating for tightly packed housing, the use of urban brownfield sites, compact cities, piazzas and public transport – all attempts to manage and make urban density comfortable. Under New Labour, this generation – architects like Richard Rogers, planners like Ricky Burdett – had the chance to implement these ideas.

You can see the results all over the UK, wherever "mixed use" blocks of flats fill former industrial land, in the skylines of Leeds and Manchester, in east London. Usually, the results entailed four- to 12-storey flats, built around squares, with mooted shops and facilities in the ground floor. An inner-city housing boom started to match its suburban precursor.

In reality, the shops and nurseries became empty units or estate agents, the squares were inept and windswept, and speculative developers crammed as many tiny flats into their plots as possible. In Stratford you can see the grimmest results – aesthetically stunted, architecturally bumptious towers crowding round wasteland. Does this invalidate the idea? Should we, as some Tories suggest in their screeds against the ludicrous myth of "garden grabbing", celebrate the end of the attempted "urban renaissance" and return to the pseudo-rural suburban sprawl of the 80s, and the depopulation and desuetude of our cities?

Or rather, should we acknowledge that the problem with New Labour, and Rogers and Burdett was that they didn't plan enough? Rather than being held to strict standards, developers were given carte blanche; instead of council housing easing the overcrowding of the poor, a percentage of allegedly affordable housing was sold in each block of terracotta-clad yuppiedromes. Meanness – "value engineering" as it is euphemistically known – was what made the New Labour landscape so grim, not height, planning or modernity, and certainly not overcrowding.