The controversial economics teacher will retire in June after 17 years as general secretary of France’s main secondary teachers’ union, the 83,000-member SNES (Syndicat National des Enseignants du Second degre) which represents just under a third of the country’s secondary teachers.

She leaves SNES after a term spanning seven education ministers (two of them serving twice, including present incumbent Jack Lang), and during which the teaching union movement experienced a violent and irreconcilable divorce.

Vuaillat earned a reputation as a hardline negotiator, inflexible with those who did not agree with her. She became the immovable object meeting an (apparently) irresistible force when the innovatory Claude All gre was appointed education minister in Lionel Jospin’s socialist-led coalition government in June 1997.

The irascible All gre proposed a series of radical reforms, including changes in the lycees (upper secondaries), to the baccalaureat and to the system of teacher transfers. He angered the union’s leadership by announcing an end to “co-management with the unions” - a reference to the clos negotiating tactics with the unions, notably SNES, practised by his centre-right predecessor, Francois Bayrou.

Personal relations between the minister and Vuaillat rapidly deteriorated beyond repair, and increasing union strikes and protests, with SNES in the vanguard, forced the minister out of office last March.

In a television interview shortly after his dismissal, All gre said of SNES: “I knew I was tackling a Stalinist union, organised with methods worthy of Moscow trials, for whom lies are customary and which twisted my words systematically to give them a disagreeable meaning.”

SNES used to be a member of the Federation de l’Education Nationale, formerly the main umbrella group uniting dozens of unions representing teachers and non-teaching staff.

But bitter ideological differences split the organisation and, in 1992, the moderate FEN leadership expelled the more militant, pro-communist organisations, including Vuaillat’s union. The following year the SNES set up its own rival federation, the Federation Syndicat Unitaire.

Since then, the FSU, of which Vuaillat was co-chair, has become more powerful, now consistently beating FEN in elections for seats representing teachers on statutory educational councils.