Rabbis have filed a lawsuit against a New York City regulation that would require a written parental confirmation for a rite called "metzitzah b'peh".

During metzitzah b'peh, the infant's blood is sucked by the person performing the circumcision (mohel). The act is seen as a way to cleanse the wound. The ritual is performed eight days after the baby is born.

"It is important that parents know the risks associated with the practice," City Health Commissioner Thomas Farley said in a statement.

In September, the New York City Board of Health passed a regulation that people performing the ritual would be required to have written consent from the parents or the guardian in which they (parents/guardian) acknowledge that the Health Department advises against the rite.

The Central Rabbinical Congress of the USA and Canada, Agudath Israel of America and the International Bris Association filed the lawsuit Thursday in the Federal District Court in Manhattan, JTA has reported.

"Not only is the Department of Health wrong about metzitzah b'peh, it is trying to enforce erroneous opinions on the people of New York City. By essentially starting a public intimidation campaign that forces private citizens to spread the government's beliefs, they are shaking the core of our democracy. We believe the courts will stop this overzealous government overreach and keep them out of our speech and religion," Hank Sheinkopf, a spokesman representing those filing the lawsuit, said in a statement, the Wall Street Journal has reported.

The oral suction of blood from the wound puts the baby at higher risk of contracting herpes simplex virus, which doesn't harm an adult but is very dangerous for the infant

According to the Centers for Disease Control and Prevention, between 2000 and 2011, 11 infants contracted herpes simplex virus infection after direct oral suction during a circumcision, of which two babies died and two others suffered from brain damage.

The department added that it had received many complaints from parents who weren't aware that the circumciser (mohel) would orally remove the baby's blood, the Wall Street Journal reported.