A Detroit professor and legal adviser to the Vatican says Catholics who promote gay marriage should not try to receive holy Communion, a key part of Catholic identity.

And the archbishop of Detroit, Allen Vigneron, told the Free Press Sunday that Catholics who receive Communion while advocating gay marriage would “logically bring shame for a double-dealing that is not unlike perjury.”

The comments of Vigneron and Edward Peters, who teaches Catholic canon law at Sacred Heart Major Seminary in Detroit, are part of a polarizing discussion about gay marriage that echoes debate over whether politicians who advocate abortion rights should receive Communion.