Gay marriage foes in the Mexico state of Jalisco are pushing for a new law that would define the concept of “family.”

Last year, the city-state of Mexico City legalized gay marriage. While gay and lesbian couples can only legally marry in the nation's most populous city, the country's remaining 31 states must recognize their marriages as valid, Mexico's highest court ruled last year.

The new effort to define family as a heterosexual unit is being promoted by the coalition of socially conservative groups Mexicanos por la Vida de Todos (Mexicans for the life of everyone) which is spearheaded by the Catholic Archdiocese of Guadalajara.

This “shield” could outlaw gay marriage and the adoption of children by gay and lesbian couples, said activists Rodrigo Rincon of Cohesion de Diversidades para la Sustentabilidad (CODISE) and Guadalupe Lopez of Lesbianas en Patlatonalli, the 25-year-old lesbian rights group.

The state of Jalisco has the nation's third largest economy and its capital city of Guadalajara is the second largest metropolitan area in Mexico with more than 4 million people.