The leading U.N. expert on freedom of religion on Monday criticized the Swiss referendum in favor of a “burqa ban,” saying that the “cloak of democracy” does a poor job hiding bigotry.

“Swiss voters have chosen the eve of the International Women’s Day to vote in a measure that violates the freedom of religion or belief and freedom of expression of women and which discriminates against women!” tweeted Ahmed Shaheed, U.N. special rapporteur on freedom of religion or belief. “A cloak of ‘democracy’ does not hide the underlying bigotry.”

In a controversial referendum, Swiss voters on Sunday narrowly approved a ban on face coverings in public, including the burqa or niqab worn by some Muslim women.