Lycee Henri-IV is the elite school of the elite. The “lycee on the hill”, so called because of its location on the Montagne Sainte-Genevi ve in Paris’s Latin Quarter, boasts a baccalaureat pass rate of 100 per cent, and most of its students are destined for the “royal route” which will ultimately lead to a diploma from one of France’s top public grandes ecoles.

Odette Christienne, headteacher of this, the oldest lycee in France, which celebrated its bicentenary in October, keeps alive its tradition of republican elitism, though this sits perversely within a state education system that has been evolving during the past 25 years towards greater quality and opportunity for all.

Henri-IV and a handful of other prestigious lycees - including Louis-le-Grand, its great rival, Chaptal, Charlemagne, Condorcet, Fenelon and Jeanson-de-Sailly -continue to operate a rigorous selection process that defies the democratic guarantee that French education policy aims to provide.

Odette Christienne speaks up for republican elitism. “Would it be right for future state managers and future heads of industry to be trained in private education?” she asked in an interview published in Le Monde.

Since 1993, all public lycees have been obliged to enrol three-quarters of their pupils from within their district (Paris is divided into six districts). But the neighbourhood approach only reinforces the superiority of the top establishments: sharp-elbowed, influential parents from the professional classes know the catchment areas, and the best schools have a self-propagating elite living on their doorsteps.

If these children fail to get into an “acceptable” school, there is always the private sector. In the case of Henri-IV, says Odette Christienne, in seconde (the first year of lycee) the 75 per cent local intake consists “in abundance, of children of intellectuals, of well-known journalists, politicians, eminent doctors, heads of lycees”.

The number of students rises each year, from six-class entry in seconde to eight-class in premiere and nine in terminale, the final year when they take the baccalaureat. During the three years, bright pupils from further afield are picked to swell the school’s ranks, to the chagrin of some lycees in the provinces.

Unlike most lycee-leavers who go on to underfunded, overcrowded university, seven out of 10 will continue in preparatory classes to train for the highly competitive entrance examinations to the grandes ecoles. These elite schools specialise in such fields as science, engineering, medicine, business studies, political science and the civil service.

This is selection at its most extreme. For most schoolchildren entering lycee, past grades will determine where they go. The majority will study for a general bac (the most academic), or they can choose a technological bac. Some will be “guided” to a lycee professionel where, in preparation for a vocational career, they will take the less demanding professional bac, which does not, unlike the first two versions of the exam, give entitlement to a place in higher education.

Bac results published annually for every school confirm a pecking order and the best-performing lycees can pick and choose between applicants. The theoretical choice that parents have over their children’s lycee often ends in disappointment as over-subscribed popular ones reject them and they find themselves at a “pariah” school.

During the past 25 years, policy has moved away from the old selective elitisim to educating increasing numbers of young people to bac level and beyond. A major step in 1975 was the introduction by Rene Haby, then education minister, of the college unique, comprehensive education at lower secondary level.

When he took over education the present minister, Francois Bayrou criticised the “college inique”, which, he said, was failing many pupils. Teachers’ representatives feared he was planning to reintroduce selective streaming at 14.

But M Bayrou’s reforms of the college, which he called the “weak link of the education system”, have concentrated on giving extra support to the slowest learners.

Like lycees, some colleges are perceived as “good”, and a form of selection operates with clued-up parents trying all kinds of ruses to get their children a place in one that they believe will maximise their chances of getting into a top-level lycee. Officially, children must attend the nearest college to their home with exceptions made only in strictly defined circumstances - a parent employed or sibling already at the school, or a course available in a rare language.

But desperate parents living outside the catchment area will not hesitate to exploit educational or political connections - it is not unknown for some of them to rent a room in the area to provide a local address.