Who are they? Where are they from?

Britain's asylum and immigration policy is in disarray. In the past week there have been nightly scenes of confrontation and black farce at the French end of the Channel Tunnel as hundreds of refugees from a nearby camp try to make it through to the British side. Nearly all fail, but come back the next night to try again. Once here, most could be expected to apply for asylum, adding to an already overburdened system with more than 100,000 unresolved cases.

Britain's asylum and immigration policy is in disarray. In the past week there have been nightly scenes of confrontation and black farce at the French end of the Channel Tunnel as hundreds of refugees from a nearby camp try to make it through to the British side. Nearly all fail, but come back the next night to try again. Once here, most could be expected to apply for asylum, adding to an already overburdened system with more than 100,000 unresolved cases.

Yet the High Court has ruled that the £4.5m Oakington centre, established in Cambridgeshire last year to speed up decisions on asylum applications, breaches inmates' human rights by holding them in detention. What was intended to be a "fast track" system has been switched to the slow lane.

The whole issue has become mired in confusion and emotion, with "economic migrant", "illegal immigrant" and "asylum-seeker" being seen as interchangeable terms. Britain is said to be a "soft touch" which is being targeted by people-smugglers.

How serious is the problem? As the illustration shows, the vast majority of refugees from the world's cruellest and most unstable regimes – Afghanistan, Iraq, Sierra Leone – flee no further than the country next door. Iran and Pakistan have more refugees than anywhere else; Guinea has absorbed hundreds of thousands of people fleeing neighbouring Sierra Leone. Those who make it to Britain, often overcoming huge dangers on the way, are by definition among the cleverest, toughest and most resourceful members of the society from which they come.

What happens to them when they get here? In Dover or Glasgow's Sighthill area, local people might claim that asylum-seekers are all too visible, but for most Britons they live in a hidden world. Many are on their own, traumatised by their past and isolated by their lack of English, but it is also claimed that industries such as construction, catering and cleaning would come to a halt without them. Eastern Europe alone may receive £2bn a year from the British black economy. But asylum-seekers often go on to make valuable contributions to Britain.