Catholic parishioners around the country were read letters this morning written by church leadership railing against an Obama administration ruling that requires employers to provide health insurance plans that include contraceptive coverage.

Churches and other houses of worship are exempt from the guidelines but Catholic hospitals, colleges, and social services fall under the umbrella of institutions covered by the decision.

Originally introduced last summer, the decision was lauded by abortion rights supporters. But Catholicism considers some forms of contraception termination of life and religious leaders say adherence would fly in the face of the tenets of their faith. Critics also charge it would be a violation of the Constitutional right to freedom of religion.

The letters were penned by individual clergy, so variations exist in what was read at each Sunday Mass, but the overall theme is unified.

One letter from the Archdiocese of Washington says, "Catholic moral teachings will be placed in the untenable position of having to choose between violating the law and violating their conscience."

In another from the Diocese of Phoenix, Arizona, a bishop calls on Catholics to stand united against the rule.

"We cannot - we will not - comply with this unjust law," it reads. "People of faith cannot be made second class citizens."

Nearly all letters found by ABC News called on parishioners to pray for a reversal.

On Jan. 19, Pope Benedict XVI told the American Roman Catholic Church they needed to understand "grave threats" posed by what he called radical secularism in politics and culture. The pontiff specifically mentioned the U.S. church struggling to be permitted conscientious objection to "intrinsically evil practices."

Earlier this month religious institutions were given a year extension to comply with the decision.

During the 2008 presidential election, then-candidate Barack Obama carried 54 percent of Catholic voters. Running mate Joseph Biden was Catholic himself. However, this campaign season has seen two strong Catholics come out of the Republican party as well: Rick Santorum and Newt Gingrich.

The National Association of Evangelicals also stands against the decision.