Tens of thousands of teachers demonstrated in Mexico City on Wednesday, many vowing to disobey an education reform passed by Congress and championed by President Enrique Pena Nieto.
Holding umbrellas under a blazing sun, the teachers marched across the capital's main boulevard, snarling traffic yet again after two weeks of protests that failed to block one of the major national reforms pushed by the Mexican leader.
Pena Nieto hailed the Senate's final approval of the legislation, saying that "thanks to your important decision, the children and youth of Mexico will have better quality education."
The law aims to improve an education system that ranks dead last in the 34-nation Organization for Economic Cooperation and Development by stripping the power of unions over the classrooms and requiring instructors to undergo performance evaluations.
Mexican teachers have been able to sell their positions or pass them on to their children, but will now face tests to get jobs and promotions.
"The inheritance and sale of posts are over," Education Minister Emilio Chuayffet tweeted. "Merit is the right way to enter and grow in a teaching career."
But the teachers argue that the tests will fail to take into account cultural differences in the country, where many often lead open-air classes in remote villages where children first learn indigenous languages.
At Wednesday's march, the teachers warned they would balk at taking the tests.
"We are entering a phase of resistance because we will ignore the evaluations," said Norma Cruz Vazquez, a union representative in the southern state of Oaxaca. "For us this is a betrayal and we will not recognize this reform."
Some 70,000 teachers have been on strike in Oaxaca since school started last month, leaving 1.3 million children without classes. Thousands of teachers from that state have set up camp in Mexico City's historic Zocalo square for the past two weeks.
"There is discontent nationwide because this reform will affect all social classes," said Rogelio Ojeda, holding a sign reading "Total Rejectino of Pena Nieto's Education Reform."
The legislation is one of the centerpieces of what Pena Nieta on Monday called the "grand transformation" of Mexico.
He has struck a pact with rival parties that has also passed a reform to open up the telecommunications sector. He now plans to introduce more politically-sensitive legislation to open the state-controlled energy sector to foreign investment.