Angeles Sánchez, a grandmother with peroxide-blonde hair, has two bullet belts slung across her chest, the stock of a wooden rifle resting against her shoulder and, like hundreds of other women gathered with her, she is dressed all in white.

“For our sons and daughters,” she shouts from a busy street corner of Mexico City’s historic centre in ­protest at the government’s plans to reform the country’s ailing oil industry. “For our country,” she cries still louder. “They are not going to take our oil.”