The women are accused of offending 'religious sentiments'. Acts which offend ‘the sentiments of members of a religious group’ carry a fine - meaning the women could be jailed for eight to 12 months.
During the procession, they carried rosary beads and wore face veils worn by devout Catholic women during religious celebrations.
Hailed as the 'Santísimo Coño Insumiso', or the 'Blessed Rebellious Vagina', they reportedly were protesting against homophobia.
This week the Spanish high court overturned a previous ruling that the trio had legitimately used freedom of expression - and branded the march ‘an offence against the Virgin Mary’.
The women were protesting during a march organised by the Spanish union the General Workers' Confederation (CGT).