U.S. President Barack Obama

The controversy over the University of Notre Dame’s invitation to President Barack Obama to speak at its commencement address next month continues, as the school president defends his decision in a recent letter to university trustees.

Opponents of the university president Rev. John Jenkins’ decision have based their argument on a statement by U.S. Catholic bishops in 2004, which says that Catholic institutions should not honor those who act in defiance of fundamental Catholic moral principles.

But in a private letter to university trustees, obtained by an anti-abortion Catholic Web site, LifeSiteNews.com, school president Rev. John Jenkins said that his decision follows the “letter and the spirit” of the statement, known as “Catholics in Political Life.” 

"This interpretation was supported by canon lawyers we consulted, who advised us that, by definition, only Catholics who implicitly recognize the authority of Church teaching can act in 'defiance' of it," Jenkins wrote last week. 

"Moreover, fellow university presidents have told me that their bishops have told them that in fact it is only Catholic politicians who are referred to in this document." 

Jenkins wrote that he had frequently said that he disagrees with the President on abortion and stem cell issues.

"If we repeatedly and clearly state that we do not support the President on these issues, we cannot be understood to 'suggest support,'" Jenkins wrote. 

The letter comes as opposition to Notre Dame’s invitation to the President gathers momentum. 

At least 32 bishops oppose the invitation, citing the President’s support for abortion rights and embryonic stem-cell research. 

This includes New York Archbishop-designate Timothy Dolan who told The Associated Press that Notre Dame made a mistake by inviting Obama, saying it sends the wrong signal to students that "we hold him up as a model to you." 

Bishop John D'Arcy, whose diocese includes Notre Dame, has also said that he will boycott Obama’s commencement speech.

President Obama, the Bishop said, “has brought the American government, for the first time in history, into supporting direct destruction of innocent human life.”  

“A bishop must teach the Catholic faith ‘in season and out of season,’ and he teaches not only by his words — but by his actions,” said D’Arcy, of the Diocese of Fort Wayne-South Bend. 

The Cardinal Newman Society, a Catholic anti-abortion rights organization, had over 263, 000 signatures opposing Notre Dame’s decision as of Tuesday morning. 

“Notre Dame has chosen prestige over principles, popularity over morality,” the petition says. “This honor comes on the heels of some of the most anti-life actions of any American president.” 

Meanwhile, President Obama is due to give a major speech on the economy Tuesday morning at Georgetown University, a Jesuit school, in which he will say that the while the economy is showing signs of improvement, “we are by no means out of the woods.” 

He is also due to be awarded an honorary doctorate from the school. LiteSiteNews said that anti-abortion activists were planning on protesting at the university.