The name on our neighbours’ doorbell is self-effacing in the extreme. “Bangladesh”, it says simply, as if the 15 or so fellows crammed into a small flat downstairs have no identities to call their own bar their nationality. Seven days a week, I see them setting off for work, mostly in pairs. They sell tourist tat at the Colosseum, a mere sword’s thrust away, suiting their wares to the weather: knock-off Aviators, flimsy tele­scopic brollies or this sweltering summer’s bestseller – Japanese-style paper parasols.

Trade is brisk until the police launch a raid. Then the Bangladeshis scoop up their sunglasses stall (a square piece of cardboard) and melt into the nearby Colle Oppio park. The police snarl from their Fiats but make little attempt to follow. Half an hour later, our neighbours emerge from hiding-places within the ruined Baths of Trajan and scurry home.

For now it seems more a game than a serious crackdown. Yet the public and government mood towards immigrants, whether legal or illegal, is increasingly ugly and next time it could be the army launching a raid. Silvio Berlusconi, the prime minister who returned to power in April on a law-and-order ticket, has now brought 4,000 troops out onto the streets of Italy’s major cities to patrol alongside the police in the fight against crime, illegal immigration and terrorism (“Posturing and window-dressing”, according to the Left). There will be 1,000 in Rome.

Round our way, at least, we are used to army fatigues, because of the famous military hospital on the Caelian Hill where we live. Until now, the convalescent soldiers have haunted local bars drinking powerful espressos. By the time you read this, they may be baton-charging the Bangladeshis.And it would be with public support. The mood has changed markedly in the two years since we moved to Rome. The city’s newly elected rightwing mayor, Gianni Alemanno, is a former Fascist youth leader whose zero tolerance approach goes down well with voters. Most hostility here is directed at the city’s estimated 9,000 Roma people rather than Asians, but even Filipino cleaners and nannies, beloved of middle-class Romans, now worry about going out.

Alemanno says that of the 40,000 crimes carried out in Rome every year half are committed by non-Italians. Popular wisdom (and no longer only ranting taxi-drivers) has it that a hard core of unspecified “eastern Europeans” – including Bosnians, Serbians and Romanians as well as the Roma Gypsies – are responsible for most of the non-homegrown crime. Many live in squalid camps (there are about 85 around Rome alone) under railway arches and motorway flyovers or on the banks of the Tiber. They send their children not to school but out to steal, beg or play the accordion on the number 8 tram before passing round the hat. Current Italian wisdom has it that the Senegalese and Bangladeshis at least sell things people might want to buy – albeit fake Prada bags and fake Chanel sunglasses – and will take no for an answer. The Gypsies will just take your wallet.

Everyone has a tale of woe. Last year, Interpol contacted my husband after he was pickpocketed near Piazza Navona. Some villain had used his cards within half an hour to book into a five-star Rome hotel for the night (American Express), buy a £500 camcorder online (Visa) and order up a Chinese take­away (MasterCard). Months later, a Romanian – possibly the original thief – was arrested on the Slovenian border, optimistically trying to re-enter Europe on an EU health card in the name of Fraser.

Their methods have changed little since the early 1990s when my wallet was snaffled by Roma girls in Florence, but their numbers have certainly swelled following the EU enlargements of 2004 and 2007.Today the Gypsies are subject to the kind of stop-and-search policing methods that would have Brixton go up in flames. I have seen two carabinieri shake down a pair of girls no older than 12 until pilfered wallets from Vatican tourists came flying from their clothes. Tele­phone tapping is also commonplace: a recent police operation in Verona trapped a Roma woman who had 123 detentions for theft under 93 aliases.

Now all Roma aged 14 or over are to be fingerprinted as part of what the government calls a “census”, supposedly aimed at improving their living conditions. Illegal camps are being bulldozed. Opposition politicians, harking back to the deportation of Gypsies to Nazi camps under Mussolini, call it persecution. To their dismay, however, opinion polls show the voters are firmly behind the government. Vigilantism is increasing, with at least one Gypsy camp in Rome the target of a suspected arson attack.

Perhaps the voters haven’t realised how many building sites, factories, restaurants and cleaning companies depend on immigrant labour. In vain, leading Italian industrialists point out that factories would grind to a halt if the hundreds of thousands of illegals were summarily thrown out. Immigrants themselves argue that the actions of a few spoil it for the hard-working, law-abiding majority, many of them second- or even third-generation whose children have known no other home. Some 40 per cent of the estimated 150,000 Roma in Italy have Italian citizenship.

Overall, though, Italy is simply uncomfortable with immigration. Certainly it doesn’t embrace the concept of the “multi­racial society”. On television, I have never seen an Asian in an advertisement and only once seen a black actor – playing a housewife giving her daughter chocolate in a scene of humdrum domestic harmony. I was sufficiently struck by it to mention the ad to an Italian friend who pointed out that the woman was, in fact, a star athlete. “She’d never get on-screen otherwise,” he claimed.

There is little integration, and more than a little xenophobia. Romans can be stand-offish even to northern Europeans. In part this may be because Italy has in recent history been a land of emigration. They’re not used to people coming the other way. Small wonder, perhaps, that our Bangladeshi neighbours seek to live under the radar where even the postman can’t find them.