France's national assembly has adopted a bill that will open entry exams for grandes écoles to students from contracted lycées in underprivileged areas.
Originally, the bill was aimed only at admission procedures for Sciences Po, the grande écoles for business leaders and top civil servants.
But an amendment by opposition centrist member of parliament Pierre-Christophe Baguet to extend its provisions to higher education as a whole was passed as well.
French education minister Jack Lang commented that "it is not normal for social origins to be the determining factor in admission".
Under the Sciences Po pilot scheme, pupils will be admitted from seven lycées - two in Creteil, two in Versailles and three from the Metz and Nancy areas of Lorraine.
Successful candidates will receive annual grants of €6,100 (£3,710) for tuition fees and €3,050 for accommodation. A total of 30 could be admitted for the first year, but 20 "is more realistic", the school said.
The number should subsequently rise to 60, representing 20 per cent of the first-year total and 15 per cent of the second-year, although the school insists there is no quota and that quality is the sole criterion.
Widening the social categories of baccalauréat graduates is the last in a series of steps to diversify the types of student admitted to Sciences Po. A quarter of the total is foreign this year, the proportion of women has been running at 50 per cent for several years, and more students now come from the French provinces than Paris. In the past, at least 60 per cent were Parisian.
Also, first-year students range from baccalauréat holders to graduates from universities and engineering or business schools. "What was lacking was a social dimension," a spokesman said. "Until now, about 80 per cent of students have come from privileged backgrounds."
The latest initiative has been contested by the student union Union Nationale Inter-Universitaire, which fears the Sciences Po degree would be devalued and contests the school's right to propose the reform.
Having passed its first reading in the assembly, the bill will now have to go to the senate before returning to the lower house of parliament for a final reading.