Two children are dead, more are injured — yet a group of ultra-Orthodox rabbis say they plan to defy a health order in the name of religious freedom.

Less than a year after a Brooklyn tot died following an ancient circumcision ritual, the rabbis say they will ignore a proposed law that would mandate parental-consent forms before performing the dangerous procedure.

Over the past decade, at least one other newborn died after contracting herpes from the rite, in which the rabbi draws blood from the penis with his mouth.

But ultra-Orthodox leaders are lashing out at the city’s “evil plans” ahead of the Board of Health’s vote next week.

About 200 rabbis signed a proclamation claiming the Health Department “printed and spread lies . . . in order to justify their evil decree.”

“It is clear to us, that there is not even an iota of blame or danger in this ancient and holy custom,” the letter states.

Most modern mohels — men trained to perform religious circumcisions, who are usually rabbis or doctors — remove blood from the baby’s wound using a sterile pipette.

But some Orthodox Jewish parents insist on an ancient “suction by mouth” ritual called metzitzah b’peh.

The city’s law would require mohels to distribute consent waivers, detailing the herpes risk, before the ritual.

Rabbi David Niederman, executive director of the United Jewish Organization of Williamsburg, said no one will comply with the law, even if it’s passed.

“For the government to force a rabbi who’s practicing a religious act to tell his congregants it’s dangerous is totally unacceptable,” Niederman told The Post.

“You’re forcing the mohel and the parent to sign a piece of paper that contradicts their religious convictions.”

Niederman said there’s no substantive evidence linking herpes and the religious ritual.

Michael Tobman, a political consultant working with several large Hasidic communities, said the waiver is no minimal imposition.

“It warns parents that the city suggests a link between the practice and serious health worries, [and] it would undoubtedly have a chilling impact,” he said.

“City government shouldn’t be doing that.”

At least 11 babies in the city have contracted the herpes simplex virus since 2000 — and two developed brain damage and two died, according to a Health Department investigation.

In July, an Orange County infant was hospitalized after contracting a deadly strain of the virus.

Earlier this year, prosecutors were investigating the September 2011 death of a Brooklyn newborn at Maimonides Hospital from Type 1 herpes.

A Health Department spokeswoman declined to comment on the rabbis’ proclamation but said, “It is important that parents know the risks associated with the practice.”