A Mexican federal court has denied home detention to former teachers' union head Elba Esther Gordillo, once a feared political operator who has been in jail since 2013 on charges of embezzlement and organized crime.

The 6th Court of Federal Criminal Proceedings says it made the ruling because of a lack of evidence necessary to guarantee home detention wouldn't allow her to escape. The ruling was made public Sunday.

Gordillo, 70, requested the home detention because of her age and health issues. Under Mexican law, people over 70 can serve home sentences.

As head of the 1.5 million-member National Union of Education Workers, Gordillo was known for her flamboyant spending and ability to swing presidential elections. She was arrested ahead of President Enrique Pena Nieto's education reform.