Roman Catholic groups on Thursday embarked on a two-week campaign of prayer vigils, rallies and other events to draw attention to what they consider government attacks on religious freedom.

Called the "Fortnight for Freedom," bishops organized the education campaign during liturgical feasts for martyred defenders of the faith. Independent advocacy groups such as CatholicVote.org and Women Speak For Themselves, have joined the effort with TV ads, videos, Facebook appeals and petition drives.

While the religious freedom campaign includes protests against state laws and policies, the bishops' immediate target is the mandate President Barack Obama announced in January that most employers provide health insurance that covers birth control. Federal officials said the rule was critical to women's health by helping them space out pregnancies.

Critics have accused the bishops of organizing the campaign as a partisan assault on Obama in an election year. But church leaders insist they have no partisan agenda and blame the timing on when federal officials approved the rule.

"In only the past few years, we've experienced rampant disregard for religious beliefs in this country," wrote New York Cardinal Timothy Dolan, in an e-book released for the "Fortnight" effort. Among the examples he cites are approval for embryonic stem cell research, legal justification for torturing prisoners and support for same-sex marriage.

"We can see that there is a loss here of a sense of truth and objective moral norms_rules of conduct that apply always, to everyone, everywhere_an infringement of religious liberty and an 'eclipse of the sense of God and of man,'" wrote Dolan, president of the U.S. Conference of Catholic Bishops.

Opponents are unconvinced. "This bishops' project isn't about religious freedom — it's about privilege," said the Rev. Barry Lynn, executive director of Americans United for Separation of Church and State. "They are asking for preferential treatment from the government, and if they are successful, it would undercut the rights of millions of Americans."

The "Fortnight for Freedom" schedule kicked off Thursday night with a Mass at the Basilica of the National Shrine of the Assumption in Baltimore, celebrated by Baltimore Archbishop William Lori. Local activities are planned across the country leading up to Independence Day.

The Diocese of Pensacola-Tallahassee, Fla., plans Masses and repeat screenings of the film "A Man for All Seasons," about Sir Thomas More, the 16th-century martyr whose feast day is this week. The Kansas Catholic Conference, the public policy arm of the state's bishops, plans a June 29 religious freedom rally at the Statehouse in Topeka. The Archdiocese of Detroit plans Masses and lectures by religious liberty experts in English and Spanish. The Archdiocese of Denver has asked Catholics to fast on the two Fridays during the initiative.

Lori leads the bishops' new religious freedom committee. The panel was formed last September in response to what church leaders viewed as inadequate religious exemptions in many state laws that authorized gay marriage and mandated contraception coverage in employers' health insurance or prescription drug plans.

The Obama mandate on contraception coverage included a religious exemption that generally allowed houses of worship to opt-out, but not religiously affiliated hospitals, charities, universities and social service agencies. Many Catholics from across the political spectrum protested that the Health and Human Services department chose the narrowest religious exemption available and urged Obama to reconsider. Liberal-leaning religious groups generally supported Obama, while more conservative leaders from other traditions backed the Catholic bishops.

In response, the president said he would require insurance companies to cover the cost instead of religious groups. However, even some Catholic allies whose support was critical to passage of the administration's health care law, including the Catholic Health Association, have called the compromise inadequate.

Last month, Catholic dioceses, charities and schools, including the University of Notre Dame, filed a dozen lawsuits against the administration over the mandate. The law firm Jones Day, which is also representing businesses challenging Obama's health care law in court, is handling the cases for the Catholic groups pro bono.

Lori has said that funding for the religious freedom campaign has come from the Knights of Columbus, the Catholic fraternal organization and life insurance agency; the Order of Malta, a Catholic order that aids the sick; and the conservative Catholic publisher Our Sunday Visitor.