Meet Vincent, a 39-year-old homeless man who was down and out six months ago but now squires tourists through little-known lanes as he tells their stories, past and present.

Despite the rain, several visitors - Australian, Dutch, Taiwanese among them - stand rapt as Vincent, who preferred not to give his last name, recounts a 19th-century revolt against the government that played out in some of the cobblestone streets on his two-hour tour.

"I'm discovering the real Paris," said Marco, a 28-year-old Mexican on a solo tour around the world. "I'm making friends and having fun. It's a perfect combination."

The programme was launched a year ago by Alternative Urbaine, a four-member start-up that aims to bring homeless back from the fringes of society.Its motto: tourism "should have a positive effect on society".

And with Paris one of the world's most visited cities - more than 27 million per year, according to the Paris mayor's office, or 12 times the city's population - the French capital abounds with potential.

Homelessness has long been a problem in the city, but the situation today is very different than it was for the old-time vagrants or colourful characters immortalised in George Orwell's 1933 classic, Down and Out in London and Paris.

People begging, living in tents, on sleeping bags or under cardboard sheets is now a common sight after homeless numbers spiked dramatically, a situation blamed on the economic crisis and a sharp rise in housing prices.

Since 2001, the number of those homeless in the capital has increased 84 percent, according to the city-run Paris Urban Planning Agency. Their latest figures from 2012 say more than 28,000 people had no fixed residence -- with a big increase in women and entire families -- while shelters or emergency accommodation could not cope with demand.

A former accountant, Vincent's slide started "after a depression" and he ended up on the street - what the French call "SDF", today's much-heard acronym for "without fixed residence" .

In February, he saw a job ad with Alternative Urbaine posted by the national unemployment office in a hostel for transients.

"I got through the interview and I was hired," said Vincent, whose tours focus on the 20th district, a traditionally working class and immigrant neighbourhood barely known to tourists on the east side of Paris.

"Then when I started doing research, I found the 20th district really fascinating. It's a neighbourhood with a heart," he tells his group in timid English, after they ask how he landed his job.

Such interaction is encouraged as part of Alternative's goal to boost confidence and nudge homeless people back into society.

"Let's play a game in this little street. Can you find a piano, a cat and an old factory?" Vincent asks, as his leads his group down the tiny Passage des Soupirs - or Passage of Sighs, a charming alleyway lined with old homes, and a few new, pocket gardens and street art.

Vincent recounts everything from the district's role in the revolutionary Paris Commune - which ruled the city briefly before it was crushed by the French army in 1871 - to its trendy present-day art collectives.

"I found it very interesting. Vincent is a good guy, he answered sometimes personal questions with a lot of grace," said Australian Tim Perkins, as the tour ended on the hill in Belleville Park with its splendid view over Paris.

Even Alice, a student volunteer who helps Alternative Urbaine with translations, was surprised. "I knew nothing about the 20th arrondissement and I've just learnt so much."

From bumpy beginnings, the tours have gained in polish and regularity, and are now held every Friday, Saturday and Sunday. And though the group has a website, news has spread mainly by word of mouth.

Now, Alternative Urbaine wants to take things up a notch and make money. "We have plans with companies to organise Paris "treasure hunts" or special trails," said founder Selma Sardouk.

But the goal is unchanged. "The aim is to help the homeless believe in themselves again, to help them create social ties and regain their autonomy," said Sardouk.

Vincent is paid 10 euros ($A14) an hour with a contract to work 10 hours a week. Since February, he has taken around 200 visitors but more importantly, said Sardouk, the job helped "put him back on the right path".

Once the summer tourist season ends, the next step for Vincent will be a training course for a new career in community outreach programmes, and hopefully a fixed abode.

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AFP