For fifteen months, more than a thousand of Paris' illegal immigrants have been squatting wherever they can, staging a mass sit-in on pavements and in buildings around the city. They are demanding one thing: the regularisation of their papers.

Having been evicted by baton-wielding police from their last place near the Republique, they moved to an empty insurance company headquarters in the 18th, a neighbourhood described aptly by a friend as 'Africa headquarters'. It is probably the only place in the world you can find a shop selling music from Guinea Bissau next to a Congolese barber next to a shop selling calabash and kola nut from Mali.

Inside the building, 1300 west Africans sit day-in, day-out while the government tries to evict them. Far from the destitute conditions in which they live, they keep up the appearance of being high-spirited, enjoying card games and the tea-ceremony which passes time so well. There are three meals a day, and everyone is friendly, happy to be together.

But in every dark corner, there is someone sorting papers, trying to get enough evidence together to show they he has been in the country for six or eight years, even if illegally. A bill from a department store from May 2003, a Metro card from July 2001, a receipt for a telephone bought in 2007. If he is lucky, very lucky, he will be able to pass the rigorous tests that illegal immigrants have to go through to become legal.

I asked one man if it was better to live in this squat, knowing he could get arrested, jailed and deported any time he goes out, than living in Mali as a legal citizen. "Yes," he said. "Because at least while I am here there is a chance I will get my papers. Then I can work." And what would he do once he got his papers and a bit of work?

"Go back to Mali."