Gordillo, who did not grant The Times an interview for this article, denied in public comments the "frivolous and slanderous" accusations, adding, "Yunes is dead to me."
Her union has not had to open its books to the public; its finances, including Gordillo's salary, are kept private. However, there are growing demands by critics and some politicians that the organization undergo an audit. Gordillo said that she'd be happy to have the finances inspected, one day, but that she won't do so under pressure.
Jorge Castaneda, a former foreign minister and author of a new book on Mexico, "Manana Forever?", estimated that the teachers union receives $10 million a month from the state.
Castaneda, who considers himself a friend of Gordillo, says her power rivals just two forces in Mexico: Carlos Slim, the world's richest man; and Televisa, the broadcasting giant that acts as a virtual monopoly.
"In contrast to her skills as a union leader," Castenada said, "is her radical inability to use her enormous power for any cause other than her own personal cause."
Cecilia Sanchez of The Times' Mexico City bureau contributed to this report.