Thousands of teachers surrounded the main studios of Mexico's two national television networks on Tuesday to demand airtime for their objections to a sweeping overhaul of education.

Members of the militant CNTE union, which represents a third of the country's public school teachers, have mounted a series of protests in Mexico City against the parts of the overhaul dealing with teacher evaluation.

The CNTE activists gathered Monday outside the Spanish, U.S. and French embassies in hope of garnering international attention to their cause.

The Mexican Congress met in special session last week with the aim of passing bills needed to implement the educational overhaul promulgated in February by President Enrique Peña Nieto.

But pressure from the teachers, who forced lawmakers to abandon the legislative chambers and meet at a convention center, effectively blocked - for the moment - approval of the measure that would institute the controversial teacher-evaluation regime.

Protesting CNTE teachers cut off road access to Mexico City International Airport for several hours last Friday. EFE