You wouldn't happen to have a spare crowbar?

A thickset bearded type, with long, matted hair, pushing 30, and wearing a blue ski jacket, is sprawled out on the battered sofa. He says he and his companions have just occupied a former supermarket in Carabanchel, a working-class district in the south of Madrid. Sitting opposite him is an older man, who hasn't taken off the beret he's wearing to protect his balding pate against the chill November weather outside. He too has occupied what he calls "an abandoned space."

Along with several others, the pair are waiting in the Casablanca social center a few meters from the Reina Sofía art gallery in central Madrid to talk to a team that offers legal and practical advice on the best way to go about occupying empty buildings.

A combination of the worsening economic crisis and a sense of political legitimacy awarded by the 15-M protest movement has seen a sharp rise over the last few months in the number of empty buildings being occupied in Spain's major cities, particularly Madrid and Barcelona.

But for many activists involved in the 15-M's myriad groups, among them platforms set up to prevent evictions, the situation is fast getting out of control. "This is all happening too fast, and in too improvised a fashion," says a volunteer at the social center.

"We need a crowbar right now to get in this apartment," a young man wearing camouflage pants can be overheard telling the two advisors, adding: "There isn't time to have a meeting every time we need to move in somewhere."

Spain's so-called okupa movement has traditionally been divided over the issue of how to interpret Article 47 of the Spanish Constitution, which states: "All Spaniards have the right to decent accommodation." In Madrid, the guiding spirit is that only properties that have been either abandoned by their owners or bought for the purposes of property speculation, and subsequently allowed to fall into disrepair are eligible for occupation. Typically, occupied buildings in Madrid have been used as social and cultural centers; in Barcelona, the okupas have been guided more by the spirit of anarchism, seeing squatting as a means of political protest and confronting the system.

In a recent article, Miguel Martínez, a sociologist at Madrid's Complutense University, describes the difference as "negotiators and radicals."

In the run-up to the November 20 general elections, the abandoned Hotel Madrid, located in a side street just a hundred meters from the central Puerta del Sol - where a tent city was set up for a number of weeks in the early summer - was occupied under the auspices of the 15-M movement, at one point offering shelter to up to 100 people who had been evicted from their homes. Two weeks after the elections, armed police sealed off the area around the hotel and threw the occupiers out, arresting several people.

In the days that followed, several empty buildings in the center of the city were occupied, since when at least one occupation has taken place each day.

"From the mid-1990s, the okupa movement was largely run by people belonging to social organizations who had clear goals and were well organized. These days the people involved are from a much wider variety of backgrounds. The economic crisis has affected a lot of people from across the social spectrum. More than 200 families are being evicted from their homes every day throughout Spain, what are they going to do, live under a bridge," says Endika Zulueta, a lawyer and veteran of the social collectives movement. The 15-M's housing section emphasizes that occupying empty properties is a temporary solution for such families, and that it is campaigning instead for longer-term solutions for families with no breadwinner that can't meet mortgage payments or pay their rent. Its approach is to use empty properties as community centers, as places to organize meetings.

"We're not talking about the storming of the Bastille here. We need to have meetings, and it is too cold to hold them in the street. We simply want to make better use of abandoned buildings," says Zulueta, who is critical of what he calls "new, heterogeneous groups," acting in their own interests. "The recent spate of occupations has been botched, badly organized," he says.

The 15-M movement is now discussing its response to the police operation that ended the occupation of the Hotel Madrid.

"We are holding meetings to discuss whether to occupy somewhere else," says a source. On December 7, two days after the police raid, those who had carried out the occupation began a series of meetings that will culminate on December 20 when legal advice on the buildings under occupation will be taken, and a policy decided. In the meantime, it's open season on empty buildings in Madrid.

For example, 15 brand new apartments in a block owned by La Caixa savings bank in central Madrid have been occupied by families evicted from their homes, along with several unemployed youths.

One of them, who prefers to remain anonymous, is critical of both the current spate of unorganized occupations, along with the legalistic approach of the traditional occupation movement centered on social centers, with its long list of dos and don'ts. "It's as though you were taking out a mortgage."

He's also choosy about the type of property he will occupy. "We don't just take over any old abandoned building."

He says that the time has come to take action against the growing number of evictions and the resulting rise in homelessness. There were 5,225 evictions in Madrid in the first half of this year, according to official sources.

The activists in today's occupation movement are continuing a tradition that began in the early 1990s with AIM, a neighborhood association that started up in the working-class neighborhood of Vallecas in response to legislation by the Socialist Party government of Felipe González in 1985 aimed at liberalizing the rental market and making more properties available. But as veteran activist Francisco Pérez points out, the aim of occupying empty buildings was to draw attention to the housing problem and the need for government policies to address the difficulties many people faced in finding somewhere to live, rather than resolve it by encouraging people to set up home in empty buildings. "I personally didn't have a problem in buying or renting, but I took part in occupations to highlight the problems others faced," he says.

Despite the growing numbers of people occupying empty buildings in Madrid because they have nowhere else to live, the social center movement retains a strong presence. The best known of these is Patio Maravillas, based in the Malasaña neighborhood, which aims to provide a range of cultural and other services to local residents, forming part of the social fabric in the process. Like the Casablanca, it offers a range of activities, among them classes in Spanish for immigrants, bicycle repair workshops, reading clubs, legal advice, and even free VOIP long-distance telephone calls. It also hosts frequent political discussions.

The most recent occupation to use an abandoned building as a social center in Madrid is a vast, four-story former cooperative supermarket known as the Eko, in Carabanchel.

After knocking at the main entrance several times, somebody finally appears. "The building has been abandoned for 12 years. There has been talk of turning it into apartments, but so far it has just remained empty. We'd like to refurbish it, and hand it over to the local residents," says a voice from inside.

After a few minutes we are allowed in, and are taken on a tour. Around 80 people are working inside, despite no running water or electricity. Most of the windows have been smashed, but there are signs of progress. Most of the volunteers are part of a local division within the 15-M movement network. This is the first time they have occupied a building, but they are in contact with other social centers in Madrid such as Casablanca, the Patio de Maravillas and the Tabacalera building in the Embajadores neighborhood of the capital, which is being used with the permission of the Culture Ministry in a ground-breaking project that has brought local government and volunteers together for the first time. "We think that what we are doing is legitimate because the government is not doing its job," says a volunteer at the Eko.

"We're not dropouts, and we're not trying to hide. The door is open to anybody who wants to join us," says a volunteer.

Across the other side of Madrid, in the San Blas neighborhood, six police vans are lined up in front of a former market that has been empty for the last decade. In October, the Montamarta market had been turned into a neighborhood social center. On December 5, the same day that the Hotel Madrid was raided, police forced out the volunteers who had set up a social center in the premises. The doors and windows have since been bricked up. Last week around 100 local residents staged a protest in front of the market, demanding that it be reopened and used as a social center, which explains the police presence.

Meanwhile, the legal team at the Casablanca social center tries to cope with the sudden rise in demand for its services, attending for an hour and a half twice a week, answering questions, offering help, and even lending tools. And of course its manual, a 62-page guide covering every aspect of how to occupy an abandoned building. It begins with a warning from the director general of the Madrid Housing Authority (IVIMA): "They are very professional, they are organized, and they know every trick in the book." By the middle of last week, it was fast running out of manuals.