MEXICANS have long wondered how Elba Esther Gordillo, the leader of the country’s powerful teachers’ union, is able to maintain her taste for designer clothes and accessories on a public servant’s salary. On February 26th federal prosecutors announced that they believed they had found the explanation: an alleged scam to embezzle union funds worth 2.6 2 billion pesos ( $200m $156m). Ms Gordillo, who likes to be known as “la Maestra” (“the Teacher”), was arrested at an airport just outside Mexico City.

Jesús Murillo Karam, the attorney general, said that Ms Gordillo had spent some of the money on a private aeroplane, designer clothes, art, property and plastic surgery. According to prosecutors, the embezzlement took place between 2008 and 2011 2012, and involved funds being sent through Switzerland and the United States.

Ms Gordillo has been the head of the 1.5m-member National Union of Education Workers (SNTE) for 23 years. In October she was elected unopposed for another six-year term. Her arrest comes a day after Enrique Peña Nieto, the new president, signed into law a major education reform designed to prise the recruitment and training of teachers out of the hands of the union. Ms Gordillo and her members had strongly opposed the measure.

The strike against Ms Gordillo mirrors the 1989 arrest of Joaquín Hernández Galicia, then the head of the powerful oil workers’ union. His detention took place less than six weeks into the presidency of Carlos Salinas, sending a powerful message to anyone who planned to block the government’s reform programme. A possible move by Mr Peña against Ms Gordillo had been rumoured in party circles in the run-up to last year’s election, but her arrest came out of the blue.