Article 51 of Mexico’s Amparo Law lists the reasons for which the judges who hear amparo cases must excuse themselves. Fraction VII reads: “Si tuvieren amistad estrecha o enemistad manifiesta con alguna de las partes, sus abogados, abogadas o representantes” (If they have a close friendship or a manifest enmity with one of the parties, their lawyers or representatives).
Article 39 of the Federal Code of Civil Procedure sets out the impediments of judges in civil cases. They include a “relación de intimidad con alguno de los interesados” (close relationship with one of the parties) and “tener mucha familiaridad con alguno de ellos” (being very familiar with one of them).