The Obama Administration’s decision to challenge the constitutionality of the Defence of Marriage Act (DOMA) in the courts could create “a national conflict between Church and State of enormous proportions” the president of the United States Conference of Catholic Bishops (USCCB) has warned.

In an open letter to President Barack Obama, Archbishop Timothy Dolan of New York has attacked the decision by the Justice Department to challenge the constitutionality of DOMA, which was signed into law in 1996 by then Democratic President Bill Clinton.

DOMA means that US states don’t have to recognise same-sex marriages entered into in other states.

Archbishop Dolan said that the decision by the Justice Department in February to stop defending DOMA in court was “problem enough, given the duty of the executive branch to enforce even laws it disfavors”.

But he expressed his extreme disappointment at “the intensification of efforts to undermine DOMA and the institution of marriage” by the Department.

He said that his letter reflected “the strong sentiment expressed at a recent meeting by more than thirty of my brother Bishops who serve on the Administrative Committee of our episcopal conference”.

Hundreds of other Catholic bishops throughout our nation shared these concerns, he added.

Archbishop Dolan said: “The Catholic Bishops stand ready to affirm every positive measure taken by you and your Administration to strengthen marriage and the family.

“We cannot be silent, however, when federal steps harmful to marriage, the laws defending it, and religious freedom continue apace.”

Archbishop Dolan’s letter came with a legal analysis which detailed the various executive activities which have given rise to the increasing apprehension of the USCCB.

The Archbishop contrasted the actions of the Justice Department against DOMA, and the values it stands for contrast with President Obama’s Mother’s Day and Father’s Day speeches earlier this year which emphasised “the critical role played by both a mom and a dad in a child’s life, and you rightly call upon society to do all it can to uphold both mothers and fathers”.

He said: “The Mother’s Day and Father’s Day proclamations display a welcome conviction on your part that neither a mom nor a dad is expendable. I believe therefore that you would agree that every child has the right to be loved by both a mother and a father.”

Archbishop Dolan also said that it was “particularly upsetting” for those who stood up for the institution of marriage to be accused of bigotry and prejudice.

He said that the Obama Administration, through “various court documents, pronouncements and policies” accused those who support DOMA of being motivated by prejudice and bias.

He added: “It is especially wrong and unfair to equate opposition to redefining marriage with either intentional or willfully ignorant racial discrimination, as your Administration insists on doing.

“We as Bishops of the Catholic Church recognise the immeasurable personal dignity and equal worth of all individuals, including those with same-sex attraction, and we reject all hatred and unjust treatment against any person.

“Our profound regard for marriage as the complementary and fruitful union of a man and a woman does not negate our concern for the well-being of all people but reinforces it. While all persons merit our full respect, no other relationships provide for the common good what marriage between husband and wife provides. The law should reflect this reality.”

He concluded by urging President Obama “to push the reset button” on his Administration’s approach to DOMA.

He said “Our federal government should not be presuming ill intent or moral blindness on the part of the overwhelming majority of its citizens, millions of whom have gone to the polls to directly support DOMAs in their states and have thereby endorsed marriage as the union of man and woman.

“Nor should a policy disagreement over the meaning of marriage be treated by federal officials as a federal offense—but this will happen if the Justice Department’s latest constitutional theory prevails in court.

“The Administration’s failure to change course on this matter will, as the attached analysis indicates, precipitate a national conflict between Church and State of enormous proportions and to the detriment of both institutions.”