Cambridgeshire police estimate that three years ago their county was home to a small handful of brothels at most. Since then they have raided and closed no fewer than 80. The wave of inward migration attracted by seasonal farm work, largely from Eastern Europe, is undoubtedly a factor behind the soaring incidence of sexual trafficking that is filling these brothels. But the problem is not confined to East Anglia. Nor do new immigrants account for all the clientele who are funding this booming but abusive industry. It is part of a trend towards greater acceptance of commercialised sex that is spreading outward from major cities as well as across rural Britain.

There are signs, none too soon, that the Government has grasped the scale of the issue. The Serious Organised Crime Agency (SOCA) is preparing to devote 25 per cent of its resources to combating people trafficking on the ground that it inflicts more harm on people and communities than any other category of crime except drugs. And next week police forces will launch a second nationwide crackdown on gangs specialising in trafficking, codenamed Operation Pentameter II. But official statistics on trafficking are sparse and confused, conviction rates are unacceptably low, and the stakes, if progress is not made against the gangs responsible, are alarmingly high: their business model aims for the establishment of a flexible criminal infrastructure that can respond to crackdowns in one area by refocusing on another.

A significant proportion of the women “rescued” in recent police raids in Cambridgeshire were EU nationals and therefore technically eligible to work legally in the UK. Effectively kidnapped, they were powerless to do so. By Home Office estimates, 4,000 women are trafficked into Britain each year. The actual number is likely to be far higher, but even among those who have escaped from brothels only a tiny minority have been persuaded to testify against their gangmasters. As a result there have been just 30 convictions under the Sexual Offences Act in the past three years.

The trafficking of women feeds a modern slavery that is thriving behind net curtains and neighbours’ averted eyes. To ease appalling suffering, but also to boost conviction rates, it is imperative to expand initiatives such as the Poppy Project in London, which provides escaped prostitutes with a refuge and a chance to gather the courage to speak out. With their help we will be better equipped to curb this cruel industry.