ATLANTA – The nation’s Roman Catholic bishops on Wednesday promised steadfast opposition to President Obama’s mandate that birth control be covered by health insurance, saying it is one of many threats to religious freedom in government.

Bishops insisted repeatedly that they had no partisan agenda. They said they were forced into action by state and federal policies that they say would require them to violate their beliefs in order to maintain the vast public-service network the church has built over a century or longer.

“It is not about parties, candidates or elections as others have suggested,” said Baltimore Archbishop William Lori, chairman of the bishops’ religious-liberty committee. “The government chose to pick a fight with us.”

The meeting of the U.S. Conference of Catholic Bishops in Atlanta is its first since dioceses, universities and Catholic charities filed a dozen federal lawsuits over Obama’s rule that employers provide health insurance covering birth control.

The provision, part of the White House health care overhaul, generally exempts houses of worship, but faith-affiliated employers would have to comply.

Federal officials have said the rule is critical to preserving women’s health by helping them space out their pregnancies.

Still, Obama has offered to soften the rule for religious employers by requiring insurance companies to cover the cost instead of faith groups. The administration is taking public comment through next week while working out the details, but bishops have said the changes proposed so far do not put enough moral distance between the church and artificial contraception.

The bishops are organizing a “Fortnight for Freedom,” two weeks of rallies and prayer services on religious freedom leading up to July Fourth. Archbishop Carlo Vigano, the pope’s ambassador to the United States, told the bishops that the advocacy effort “has my full support.”

Vigano noted that the religious-freedom push required a “delicate” approach in the context of a presidential election. But the ambassador said the concerns were so worrisome that bishops had to act. Church leaders gave Vigano a standing ovation.

Many Catholics across the political spectrum have said they agree that a broader religious exemption is needed for the mandate, but have still raised questions about the church’s strategy of lawsuits and rallies.

“Most bishops don’t want to be the Republican party at prayer, but their alarmist rhetoric and consistent antagonism toward the Obama administration often convey that impression,” said John Gehring of the liberal advocacy group Faith in Public Life.