I’ve heard some excellent things about our Home Secretary, Theresa May. People who work in her department say she’s bright and hard-working, and that she runs around on her hamster wheel of ministerial duties as nimbly as any political hamster could be expected to.

If she has a fault, it’s said, it’s that she doesn’t have a grand plan — the Home Office wheel spins round, but to no particular end.

Well, that’s all to the good, say my sensible friends — who wants a reforming secretary of state? No good can come of a politician with ideas. It’s the one approving thing also said about Cameron: at least he doesn’t have an agenda.

Well, I’m not so sure that isn’t a stupid thing to say. There are casualties of reform — but there are casualties of aimlessness, too, and these are often the least deserving. If, for instance, the Home Office has no real idea about who or why it wants to deport, then any old sap will do.

I’ve an example up my sleeve, a man I’ll call Marc for fear of getting him into trouble again. He’s an interesting man, Marc, good-looking, self-sufficient, stubborn as a goat. He’s from France but he sleeps rough in London because, in the grand tradition of stubborn Frenchmen, he chooses to be an outsider, and also because he has a vocation.

Marc’s vocation is to appreciate art, modern art in particular, and it’s why he’s in London, home of the Young British Artist. If there’s an exhibition at the Whitechapel, an installation in the Heywood, a new Antony Gormley at White Cube, Marc will have seen it 20 times. If you visit the Turbine Hall of a weekend, the chances are that Marc has occupied a space in your peripheral vision. I think of him like the Catcher in the Rye: the Watcher at the Tate. And rather him than me, I think every day as I bike past the giant blue chicken in Trafalgar Square.

Does Marc, a Frenchman, have a right to live in London? He’s always assumed he does. There’s such a fuss made about the right to free movement within the EU that I thought he did too and I’m quite sure all the other homeless men and women in London from Europe (that’s more than half of all London’s rough sleepers) assume the same. At any rate, Cameron has said ‘each case will be judged on its own merits’ and for Marc that should be a clear-cut ticket to reside. He’s well known in his neighbourhood for directing tourists and helping binge-drunk chicks in their Thursday comas on to the right night-bus home. An article in Time Out once listed ‘London’s top ten secrets’. Secret seven was: ‘A guardian angel by bus stop X who directs the lost, late at night.’ Marc is London’s secret seven.

Late last year, in the early morning, Marc was approached by agents from the UK Border Agency, the branch of the Home Office that hoofs people out of the country. They told him that he was to be deported, and left a notice to that effect on his bag. Marc was confused: where would they deport him to, given that he’d never shown them his passport or said where he was from? The official notice said he was to be sent to ‘In or around France’.

Had Marc been a member of a Somali criminal gang, or an Islamist plotter, perhaps he’d have had a lawyer on speed-dial and Article 8 of the ECHR — protection for private and family life — off by heart. He might have cried ‘racism’, which is Theresa May’s greatest fear. A cannier man would also have skedaddled sharpish from his usual spot. But Marc stayed put and a few weeks later he was bundled into a van and driven off to the Immigration and Removal Centre at Colnbrook near Heathrow. When I went to visit, he’d been moved again, to the IRC in Plymouth. ‘God knows why,’ said a nice man in Colnbrook. ‘That’s usually for criminals or long-term cases.’ I was considering the trek to Plymouth when Marc was transferred again to IRC Harmondsworth, then flown back (with three accompanying officers) to the city that some border agent had decided was his home.

As it happens, I think Marc was deported illegally. It’s true, now I come to look it up, that he only has a right to reside without finding a job for three months, but there’s an exception for those who can prove they’re not ‘an unreasonable burden on public funds’. Marc — and for that matter all the other hundreds of rough-sleeping Europeans in London — have no fixed address, so no government cheque. They’re less of a burden on our state than anyone on Benefits Street, though much easier to deport.

So I think an injustice has been done, but (forgive me, Marc) I’m more worried about what on earth the whole charade was for. It cost about £100 a night to put up Marc in the various IRCs. Then there’s transport around the shop to Plymouth and back and three flights to ‘in or around France’. Not much change from £4,000, I’d have thought — and no one, even and especially not the Border Agency officials, thought there was any point to deporting him at all.

When I next heard from Marc, he was back in London again. He told me that the officials who’d flown with him had reassured him that he could, perhaps should, just turn around and come straight back. Take the next flight home, said one — you’re not a criminal, they can’t stop you. So Marc bought a bus ticket back to London, though he stopped on the way to take in a few new exhibitions. He’s back in his usual spot now, but he quite enjoyed his jaunt, he says, and might be up for another, as and when the Home Office feel the need to chalk up another easy score on the deportation board.