PICTURE living in a shipping container six metres long by two metres wide. Now imagine that you are a family of eight. You must eat, sleep and go to the bathroom in the same space - in a Middle Eastern summer.

What privacy remains inside these "homes" is further diminished by the fact that they are stacked in two-storey rows of 10, putting families literally either above, below or right next door to each other.

Such are the living conditions for 31,000 Palestinian refugees at the Nahr al-Bared camp in Lebanon, about an hour's drive north of Beirut.

"It's so hot in here in summer that you cannot think," says 26-year-old Ahmad el-Haj, whose wife is pregnant with their second child.

Sitting down to dinner on the floor of his one-room home, the only possessions that el-Haj has are the clothes hanging on the line outside, the mats he and his wife sleep on and the crockery stacked in the cupboard behind him. "You hear everything your neighbour does, you see everything and it never ends."

When the original camp was demolished by the Lebanese Army in May 2007, after a showdown with Islamic insurgents, the container-style accommodation was meant to be temporary.

Two years later, the camp's residents are still awaiting final approval from the Lebanese Government before work can begin to rebuild their homes.

"I am a refugee twice. This is the second time in my life that I lost my home," says Rasmia Yehia, who was 17 when the 1948 Arab-Israeli war drove her family from what is now northern Israel.

Over the weekend, Palestinians across the world have commemorated the 61st anniversary of al-Nakba, the "catastrophe", the formation of the state of Israel and the beginning of lives in exile for millions of their countrymen.

For Yehia, her second time as a refugee "was more difficult because I only lived in Palestine for 17 years, but I have lived here [in Lebanon] for 60 years."

Not that life was much better in the old Nahr el-Bared. Like the 11 other Palestinian refugee camps in Lebanon, Nahr el-Bared was a condensed and dilapidated patch of squalor.

Of the 4.6 million Palestinian refugees spread across 58 camps in five locations - Lebanon, Syria, Jordan, the West Bank and the Gaza Strip - conditions for the 422,000 living in the Lebanese camps are considered the worst.

Palestinians living in Lebanon have no right to citizenship, no right to vote and are explicitly banned from buying private property. To move from one camp to another, Palestinians require a special permit.

Apart from menial labour and some clerical jobs, Palestinians are barred entry to a list of 74 professions including law, medicine, engineering, teaching and journalism.

A Lebanese woman who marries a Palestinian will lose the right to pass on Lebanese citizenship to her children.

For basic services, such as health or education, Palestinians in Lebanon depend on the UN Relief and Works Agency. "We are like a small government," says Hoda Elturk, the agency's manager of public information in Lebanon. "Meant for one or two years, we are still here after 60."

Partly because of Lebanon's precariously balanced system of democracy and partly because many Lebanese blame the Palestinians for dragging the country into a bitter, 15-year civil war that began in 1975, there is little sympathy among ordinary Lebanese for the plight of Palestinian refugees and their descendants.

The largest refuge camp in Lebanon is Ain al-Hilweh, with a population of about 80,000 people crammed into just a few square kilometres.

Close to the Israeli border, Ain al-Hilweh also has the reputation for being the toughest and meanest of the camps and of being "armed to the hilt".

"It is a very tough existence," says Mohammed Fadi, 44, a history and mathematics teacher who spent his first 31 years inside Ain al-Hilweh and now teaches at one of the camp's schools. "But it's not tragic. The life has its taste. When you live so close to your families, and your neighbours for so long, it becomes a strangely comforting part of life."

But, according to Fadi, it is in places such as Ain al-Hilweh that armed resistance is born.

"When people ask why Palestinians might turn to violence, it is because for many there is nowhere else to turn to."