Judge Loretta Giorgi was reacting to a court appeal against the measure presented by several Jewish organisations and the city attorney. Jewish and Muslim groups had objected to the proposal because it clashes with ancient religious practices to circumcise male infants.

Anti-circumcision activists - calling themselves "intact-ivists" - had placed the proposal on the citywide ballot in May for an election scheduled to take place in November.

The ban would have made it illegal to "circumcise, excise, cut or mutilate the whole or any part of the foreskin, testicles or penis of another person who has not attained the age of 18 years."

The ban would have made exceptions for medical reasons but not for religious practises. Violations would have been punishable by a maximum of a 1,000-dollar fine and one year in jail.