State borders hold a place in the collective imagination of our times in which anxiety plays a central part. It is at borders that the mundane certainties of life dissolve and the simple business of existing becomes a matter of uncertainty. This is the place where a person is forced to confront with the sharpest of intensity the fact that the rights which usually seem as securely available as an intimate personal possession are in fact a by-product of their relationship with the authorities of a state. It is at the border that this relationship can be called into most fundamental question. “I see you are in possession of a British passport madam”, says the immigration officer. “But can you explain to me how you came by this document and why you feel you are entitled to benefit from it?”

This is a disconcerting question that few of us would feel confident of answering (certainly without detailed knowledge of the provisions of the British Nationality Act 1981). Most of us are in the happy position of being unlikely to be pushed too far on the matter. But some are not. For example, one young man I assisted with legal advice told me of his anxious hours at Heathrow airport when his claim that he was British-born, if not raised, was treated with deep scepticism. He had been born in Britain, but when he was six years old his Guyanese parents had taken him to their home country after a decade of life in London. Now returning to study at university, his case was only resolved after his lawyer intervened with additional evidence of his personal circumstances.

But if a British citizen can be subjected to this level of stress, how much greater are the anxiety levels for a Filipina nurse questioned about a visa that is probably incomprehensible to her – supplied by an agent back in Manila, who has assured her that it entitles her to come to the UK to accept the offer of a job as a nurse. It is entirely possible that all the deals that have been done – the form-filling, the gathering of supporting documents, the photographing, the English testing, the finger-print taking, and the payment of often very considerable fees, will be picked apart by an assiduous official who routinely finds grounds for doubting that a young woman from northern Santa Teresita could ever have been awarded a degree in health care from the country’s prestigious De La Salle University.

At a border you can be mentally stripped naked through rigorous interrogation, before being taken to a small room where you are physically stripped. Diaries will be read and hard drives on laptops scrutinized; while the letter from your cousin offering you a sofa to doss on until you sort out your own place will be the subject of excited interest, in case it reveals a snippet or two about why you are “really” here. When things go wrong for you at a border you lose the right to tell your own story of your life. You see another you being assembled before your very eyes, through which you are presented as a monster of conniving malevolence, capable of any deceit in your efforts to lay your hands on something to which you have no entitlement. The worst thing is that you are invited at each stage to follow the logic of this deconstruction of yourself. By the end you may find yourself morbidly agreeing that, “yes, I can see how you would believe that of me …”.

In short, a border is a place where most of us don’t want to be for any longer than the time it takes to clear the queues at immigration control, pick up your luggage and board the bus to the centre of town. As the border gets further behind you with each passing minute, you return to a world which may have its everyday worries and concerns, but in which there is at least the assurance that, in normal, mundane intercourse, the default presumption is that you are who you say you are.

But nowadays, for increasing numbers of people, this is not what happens. The border is no longer something to be negotiated on the relatively few occasions in life when we make a conscious decision to approach it and hazard all its dangers. Those disconcerting immigration officials are now being given leave to absent themselves from passport checking duties: they are being sent off in minibuses to ply their trade in many of the places where ordinary folk need to go as part of their daily lives. People may now be asked to verify their immigration status when they apply for a tenancy, or to university, or for child support, or even at the tube station.