The main Modern Orthodox rabbinical association says a prominent member violated its rules by participating in the National Prayer Service on Jan. 21.

A Rabbinical Council of America official said that Rabbi Haskel Lookstein, the religious leader of Congregation Kehilath Jeshurun in New York City, broke the organization’s rules by participating in the

service at the National Cathedral in Washington, D.C., on the morning after President Barack Obama’s inauguration.

“The long-standing policy of the Rabbinical Council of America, in accordance with Jewish law, is that participation in a prayer service held in the sanctuary of a church is prohibited,” the RCA said in a statement. “Any member of the RCA who attends such a service does so in contravention of this policy and should not be perceived as representing the organization in any capacity.”

The RCA said that Lookstein’s participation was problematic both because the service was held in the sanctuary of a church, which Orthodox Jews are prohibited from entering, and because it was an interfaith prayer service, which the RCA discourages for fear that such participation could allow missionaries to legitimize their argument that Jews can indeed embrace Jesus.

“To go into a cathedral, in this case an Episcopalian cathedral in the main sanctuary, is certainly by most accounts not appropriate,” said Rabbi Basil Herring, the executive director of the RCA.

Herring was adamant that the RCA was not taking a political stance, noting that the organization sent a letter to Obama congratulating him and expressing confidence that “with the help of God, you will build on the respect and good will that you have earned to lead a united country in a successful confrontation with the daunting challenges that we face both within and without.”

The RCA has been in conversation with Lookstein, but was not seeking to sanction him, said a source familiar with the situation. But, the source added, any RCA member can suggest that another member be brought before a disciplinary board for violating rules. It is not clear if any member intends to do so.

In the service at the National Cathedral, Lookstein joined six representatives of various religious communities, including Rabbi Jerome Epstein, the executive vice president of the United Synagogue of Conservative Judaism, in reciting portions of a nondenominational responsive prayer. Most of the overall service was nondenominational, but there were a few distinctly Christian references.

Lookstein said he was satisfied with his decision to participate.

“After consultation with people who are absolutely committed to halachah, I had originally decided to do it because I felt it was a civic duty to honor the new president of the United States. That is why I originally agreed to do it,” Lookstein said.

He added, “The people who spoke to me about it indicated it was an important contribution to the Orthodox community, because it is only right for the Orthodox community to be supporting the president in a visible way when he is [also] being supported by representatives of the Conservative and Reform movements.”