Which European politician said in July that his country was “suffering from 50 years of lax immigration rules that have led to a failure of integration”? Was it Geert Wilders, the Dutch anti-Islamic populist? Was it Umberto Bossi, leader of Italy’s Northern League? Perhaps it was Thilo Sarrazin, the Social Democrat who appears likely to be dismissed from the board of Germany’s Bundesbank for making provocative remarks about immigrants?

Actually, the speaker in question was Nicolas Sarkozy. But the fact that the French president’s comments could just as easily have come from the lips of prominent public figures in Germany, Italy and the Netherlands illustrates how a culturally defensive approach to immigration is shared across a significant part of the western European political spectrum, not to mention society at large.

It is a mood that, over the past 12 months, has caused Swiss citizens to vote for a ban on the construction of minarets. It has prompted the governments of France and Belgium to take steps to prohibit the wearing of face-covering veils. It has encouraged the French state to launch a crackdown on Roma migrants, following on the heels of a similar initiative in Italy.

Largely because of fears that millions of Muslim Turks might seek homes, jobs and welfare benefits in western European cities, it has caused public support to drain away for Turkey’s efforts to join the European Union. Finally, it has driven Mr Sarrazin’s newly published book, Deutschland schafft sich ab (“Germany does away with itself”), an anti-immigrant diatribe, to the top of the bestseller list on the German-language site of Amazon, the online retailer.

After two tumultuous years in which first Europe’s banking system and then its monetary union came close to collapse, one might think that European politicians face more pressing tasks than the suppression of new minarets, the elimination of veils or the expulsion of a few thousand Roma. But it is no coincidence that, as Europe’s economic performance has gone into relative decline in the era of globalisation, so its sensitivities on questions of identity and culture have grown more acute.

Low birth rates, ageing populations and pressure on the public finances to pay for future pension and healthcare entitlements aggravate these anxieties. Slowly but surely, the perception has arisen that the “native” cultures of France, Germany, Italy and the Netherlands are at risk of being swamped by tides of immigrants who breed more than the indigenous majority and who are neither willing nor able to assimilate.

This perception, visible in the UK as well, has obvious racist foundations but does not always represent racism in its purest form. Pim Fortuyn, the populist Dutch politician who was murdered in 2002, criticised his nation’s open immigration policies partly on the grounds that many Moroccan and Turkish immigrants rejected Dutch values of social tolerance and sexual liberalism. Similar concerns about the conservative attitudes of Muslim immigrants, especially in relation to women’s rights, are visible in Sweden. All this is a rather different matter from the explicitly far-right stance of parties such as France’s National Front, with its roots in the collaborationist Vichy regime of the 1940s and its support from the embittered pied-noir colonists who returned to France after the Algerian war of independence.

Even so, Europe cannot have it both ways. On the one hand, Europeans want to protect their high living standards and their social and economic model, blending free enterprise with a generous array of state-supplied public services. On the other hand, they want to ring-fence their national cultures with controls on immigration. But Europe’s feeble demographic outlook makes the first goal incompatible with the second.

No country better exemplifies this contradiction than Germany. “The Turks are taking over Germany exactly as the [ethnic Albanian] Kosovars took over Kosovo – with a higher birth rate,” says Mr Sarrazin. “I don’t want the country of my grandchildren and great-grandchildren to be largely Muslim, or that Turkish or Arabic will be spoken in large areas, that women will wear headscarves and the daily rhythm is set by the call of the muezzin.”

Mr Sarrazin is preoccupied by expert models that predict a fall in Germany’s population, now about 82m, to roughly 70m by 2050 and – assuming unchanged birth rates and no more immigration – a further slump to as low as 24m by 2100. Such assumptions are doubtless open to question, but it remains a fact that Germany’s average annual ratio of eight births per 1,000 women is the lowest in the world. Crucially, however, the memory of Nazi schemes to promote motherhood continues to inhibit governments in Berlin from urging women to have more children.

In spite of these trends, Mr Sarrazin is plainly exaggerating when he forecasts a Germany dominated by mullahs, headscarves and the Turkish language. Turkish emigration to Germany has declined dramatically since the start of this century. In 2008, the latest year for which figures are available, there was actually a small net movement in the other direction.

Moreover, if it is accepted that assimilation has not proved wholly successful, much of the explanation lies in the restrictive citizenship law that Germany applied until 2000. The new law, making it easier for children born in Germany to Turks and other foreigners to acquire citizenship, has proved a promising motor of social integration.