Jewish and Muslim groups in Germany have expressed outrage over a court ruling delivered on Wednesday that deemed circumcision equivalent to grievous bodily harm.
The groups said the ruling infringed on religious freedom and could lead to "circumcision tourism".
A Colonge city court ruled that circumcision violated a child's "fundamental right to bodily integrity" and that this right outweighed the rights of the parents.
The ruling is not binding but legal experts said it appeared to clarify a grey area in the law and will guide doctors in the future.
"The religious freedom of the parents and their right to educate their child would not be unacceptably compromised, if they were obliged to wait until the child could himself decide to be circumcised," the court said.
"The body of the child is irreparably and permanently changed by a circumcision. This change contravenes the interests of the child to decide later on his religious beliefs."
The case involved a four-year-old Muslim boy who was circumcised at the request of his parents but was later admitted to hospital with bleeding.
The doctor was charged and tried for grievous bodily harm but was acquitted on the grounds he had parental consent.
Prosecutors appealed against the decision but the doctor was again acquitted, this time owing to the imprecise nature of the law.
Jewish and Muslim groups were quick to go on the offensive against the court's decision.
"This ruling is an outrageous and insensitive measure," said Dieter Graumann, head of the Central Committee of Jews. "Circumcision of newborn boys is a fixed part of the Jewish religion and has been practised worldwide for centuries. This religious right is respected in every country in the world."
He added that it was "an unprecedented and dramatic intervention in the right of religious communities to self-determination."
The committee also called on the German parliament to protect the "freedom of religion".
Jewish groups were supported by leaders of Germany's large Muslim population "I feel the decision is discriminatory and counters efforts to promote integration," said Ali Demir, chairman of the Islamic Religious Community in Germany. "This is a harmless procedure that has thousands of years of tradition and a high symbolic value.
"We will end up with circumcision tourism to neighbouring countries," he added.
Aiman Mayzek, chairman of the Central Council of Muslims in Germany, said: "Religious freedom is very important in our constitution and cannot become the pawn of a one-dimensional ruling that also further strengthens existing prejudices and clichés about this issue."
The World Health Organisation has estimated that nearly one in three males under 15 is circumcised.
Thousands of young German boys, mainly from the country's Jewish and Muslim communities, are circumcised each year. The country has around four million Muslims and 105,000 Jews, and a 2007 study found that 10.9 per cent of males aged between 0 and 17 had been circumcised.
While equating ritual circumcision with grievous bodily harm the Cologne court said that practice is acceptable on medical grounds.
Although rare in Europe, circumcision is common in the United States. Around 55 per cent of males undergo the operation in America, mainly for reasons of hygiene.