Calling the Obama administration's mandated insurance coverage for contraceptives an "assault" on religious freedom, Pennsylvania's 10 Catholic bishops have urged Catholics statewide to make Friday, March 30, a day of prayer and fasting.

"On that day, offer your sacrifice for the cause of religious liberty, that the Church may be granted the basic right to practice what she preaches, and for our political leaders, that their eyes may be opened to the rights of all Americans," the bishops said in a letter issued last week and read Sunday at some parishes in the Archdiocese of Philadelphia.

The bishops assert that the federal mandate requiring health insurance companies to cover contraceptives "punishes the Church for its firmly held beliefs."

Catholic leaders have denounced the regulation because the church holds that artificial contraception and sterilization are morally wrong.

The two-page letter was generated by the Pennsylvania Catholic Conference (PCC), a lobbying and advocacy group based in Harrisburg. Its members are the state's eight Roman Catholic diocesan bishops, the Philadelphia-based Ukrainian Catholic archbishop, and the Byzantine-rite archbishop, in Pittsburgh.

Archbishop Charles J. Chaput, head of the Roman-rite Archdiocese of Philadelphia, is president of the PCC and has been an outspoken critic of the White House's mandated contraceptive coverage, which he has called "flawed and dangerous."

While fasting on Fridays is a Catholic Lenten tradition, its use in a political controversy is without recent precedent, according to officials at the archdiocese and the PCC.

"All the bishops decided this is a very serious issue," said Amy Hill, spokeswoman for the Catholic Conference. She said it had been in the works for several weeks.

"We're asking Catholics who are already observing Lent to take it the next step."

Hill also said the effort was not an attempt by the bishops to embarrass President Obama in an election year. "We didn't start it. We didn't ask for this," she said.

Steven Bozza, director of the Archdiocese of Philadelphia's Respect Life Office, called the use of Lenten practices "unusual."

"But extreme situations call for extreme responses," he said.

The Philadelphia archdiocese is also urging its members to join in a "rally for religious freedom" March 23 at Independence Hall. That event, scheduled for noon, is sponsored by the independent Pro-Life Union Inc. of Southeastern Pennsylvania.

Originally announced Jan. 20 by the U.S. Department of Health and Human Services, the federal mandate would have required all employers - including religious universities, charities, and hospitals - to provide free coverage of contraceptive devices and optional sterilization procedures, such as tubal ligations and vasectomies.

After a storm of protest from various religious groups, including the United States Conference of Catholic Bishops, Obama said last month that his administration would instead require insurance companies to provide separate coverage.

The groups have called his proposal as a false compromise.