The livestock sector accounts for 14.5% of global greenhouse emissions. Using an online survey experiment (n = 1200) in Italy, we examine respondents’ willingness to support a public petition for a meat tax sponsored by a nongovernmental organization (NGO) after priming them with information on the environmental impact of meat and an embedded moral message. Aiming to test whether institutional authority enhances the appeal of the moral message, we include Pope Francis (a religious authority) and a Professor of Philosophy (a secular authority) as the treatment frames along with a no-messenger (control) frame. Overall, support for meat tax is not significant in any of the treatment frames. However, highly religious individuals (those that practice and intensely believe in religion) across denominations and frames are more supportive of the meat tax. Moreover, we also find that there is a slight backlash among highly religious individuals when they receive the message with the Pope as messenger.