Education minister Claude Allegre last week unveiled his controversial reform for upper secondary schools amid fresh calls from some teacher unions for his resignation and for more protest strikes.
The "Lycee for the 21st Century" charter will shorten classroom hours, reduce class sizes and give help to first-year pupils in difficulty.
The reduction in the number of pupils per class, notably in the first year, is a fundamental objective of the reform," it states.
No new posts will be created, but teachers will be urged to work in teams, and keep their course-work down to 18 hours a week.
Classroom hours will be reduced to an average of 26 a week in general lycees and 30 in technical establishments, with top-up options.
The charter gave no deadline for reducing first-year classes to 30 pupils, but said third or final year classes would be down to a maximum of 35 by September. This is the first time limits have been imposed.
Arts workshops will be introduced and sports increased. Civic education will be restored and will be included in the baccalaureat exam, language courses will be divided into two and native speakers will be recruited.
The changes will be phased in over three years, starting with first-year pupils next September.
Two teacher unions, the SNES and the SNALC, oppose the proposals. The SNES said any reform must be preceded by an increase in resources. The SNALC claimed it would lower standards. Altogether 2,000 posts would have to be created to achieve the first-year class reductions, said SNES secretary-general Monique Vuaillat. Parent associations and other unions are in favour of the plan, but have said it does not go far enough.
Mr All gre has been under pressure from teachers and researchers to resign for some time, and speculation continues over whether he will lose his job in a government reshuffle.
In an interview in Science magazine last Friday, he played down the criticism: "It is very difficult to reform education in this country, but I have the confidence of the government, so I am not very troubled about the resistance."
The SNES, which has drawn up its own proposals inspired by "the Anglo-Saxon model", has called for a strike on March 15.