By Hugh Schofield in Paris

Fulfilling a pledge he made before his election a year ago, the socialist mayor of Paris, Bertrand Delanoe, has started buying up luxury property in chic neighbourhoods of the capital for conversion into low-rent accommodation for the working classes.

So far his council has acquired eight buildings for a cost of 45.58 million euros (�27.3m), and is renting three more, thereby putting several hundred new apartments on the housing list.

The biggest fault of my predecessors as mayors was to force so many Parisians to leave and thus to shatter the city's balance

Bertrand Delanoe

All the new property is situated in the "beaux quartiers" of the west and centre of the city.

One building is in rue Washington, just off the Champs Elysees in the 8th arrondissement. Another is on Avenue Mozart in the super-rich 16th.

Needless to say residents there are not exactly delighted. They say the policy is an experiment in social engineering that will benefit no-one.

Compulsory levels

Housing prices are distorted, while those who move in find themselves set outside their customary commercial or cultural frameworks.

But Delanoe is unbowed.

"The biggest fault of my predecessors as mayors was to force so many Parisians to leave and thus to shatter the city's balance. All I can do is stop the exodus - especially that of young families," he said recently.

Delanoe: Says he is applying the law

Delanoe's initiative stems from national legislation that was passed by France's left-wing government in December 2000. Entitled the "Law for Solidarity and Urban Renewal", it makes it compulsory for communes of more than 50,000 people to have rent controls in at least 20% of the housing stock by 2020.

The aim is to standardise the principal of "social variation", and prevent neighbourhoods slipping into either very rich or very poor ghettos.

If it risks alienating the haute bourgeoisie, Delanoe is not overly concerned because they never voted for him anyway

In Paris, Delanoe took the law as applying not to the city as a whole, but separately to the 20 arrondissements, which till now have had widely different social identities.

Thus the city as a whole has a level of 15% social housing (or HLM - Habitations a Loyer Modere).

But in the 19th and 13th arrondissements in the east the figure is 30%, while in the elite 7th and 8th arrondissements it is less than 1%.

The aim is now to make the obligatory 20% figure apply evenly across the whole of the city, and if it risks alienating the haute bourgeoisie, Delanoe is not overly concerned because they never voted for him anyway.

Political issue

The way Paris manages its housing stock has always been a highly political issue.

The previous right-wing administrations of Jacques Chirac, now French president, and his heir Jean Tiberi were widely accused of encouraging the flight to the suburbs of those least likely to vote for them.

The huge demand for subsidised flats also created tempting possibilities for corruption.

Few families living on normal French salaries can afford commercial rates in Paris, so HLM apartments are highly prized.

There is certainly so social stigma attached to them.

'Flats for votes'

But in the ancien regime this gave rise to widespread abuses. Queue-jumping for favours was the least of it. In the 5th arrondissement the town hall was accused of only handing out apartments to people who voted for Chirac's RPR.

Today there are still 93,000 requests for homes pending at the Paris HLM office - a figure Delanoe hopes to bring down gradually by acquiring 3,500 new homes every year.

He could do it more quickly, of course, if he spent the whole of the housing budget in poorer neighbourhoods, instead of investing in the 8th and the 16th.

But that would be to perpetuate the city's already flagrant east-west divide.