The Rev. Gerald Chojnacki, head of the New York Province of the Society of Jesus, said in a letter to his priests that he was asking bishops to tell Vatican officials who are drafting the policy "of the great harm this will cause many good priests and the Catholic faithful."
Chojnacki wrote in the letter, dated Monday, that he had participated in the funerals of several gay Jesuit clergy over the last few years.
"I find it insulting to demean their memory and their years of service by even hinting that they were unfit for priesthood because of their sexual orientation," he wrote.
Chojnacki said he would be working with the Conference of Major Superiors, which represents leaders of religious orders in the United States including the Jesuits, Franciscans and others, and with bishops to fight "for the opportunity of a gay person to say yes to God's call in celibate service of priesthood and chaste religious life."
A priest who supports the protest provided the letter to The Associated Press. A spokesman for the New York province did not respond to a request for comment Friday.
A Vatican official said last week that the upcoming "instruction" from the Vatican's Congregation for Catholic Education will reaffirm the church's belief that homosexuals should not be ordained.