In a flood of lawsuits, Roman Catholics, evangelicals and Mennonites are challenging a provision in the new health care law that requires employers to cover birth control in employee health plans -- a high-stakes clash between religious freedom and health care access that appears headed to the Supreme Court.

In recent months, federal courts have seen dozens of lawsuits brought not only by religious institutions like Catholic dioceses but also by private employers ranging from a pizza mogul to produce transporters who say the government is forcing them to violate core tenets of their faith. Some have been turned away by judges convinced that access to contraception is a vital health need and a compelling state interest. Others have been told that their beliefs appear to outweigh any state interest and that they may hold off complying with the law until their cases have been judged. New suits are filed nearly weekly.

"This is highly likely to end up at the Supreme Court," said Douglas Laycock, a law professor at the University of Virginia. "There are so many cases, and we are already getting strong disagreements among the circuit courts."

President Obama's health care law was the most fought-over piece of legislation in his first term and was the focus of a highly contentious Supreme Court decision last year that found it to be constitutional.

But a provision requiring the full coverage of contraception remains a matter of fierce debate. The law says that companies must fully cover all "contraceptive methods and sterilization procedures" approved by the Food and Drug Administration, including "morning-after pills" and intrauterine devices whose effects some contend are akin to abortion.

As applied by the Health and Human Services Department, the law offers an exemption for "religious employers," meaning those who meet a four-part test: that their purpose is to inculcate religious values, that they primarily employ and serve people who share their religious tenets, and that they are nonprofit groups under federal tax law. But many institutions, including religious schools, do not meet those criteria because they employ and teach members of other religions and have a broader purpose than inculcating religious values.

"Ninety-nine percent of women use contraceptives at some time in their lives," said Judy Waxman, a vice president of the National Women's Law Center, which filed a brief supporting the government in one of the cases. "There is a strong and legitimate government interest because it affects the health of women and babies."

The departments of Justice and Health and Human Services declined to comment.

A compromise for religious institutions may be worked out. The government hopes that by placing the burden on insurance companies rather than on the organizations, the objections will be overcome. Even more challenging cases involve private companies run by people who reject all or many forms of contraception.

The Alliance Defending Freedom, a conservative group, has brought a case on behalf of Hercules Industries, a company based in Denver that makes sheet metal products. It was granted an injunction by a judge who said the religious values of the family owners were infringed by the law.

The timing of these cases remains in flux. Half a dozen will probably be argued by this summer, perhaps in time for inclusion on the Supreme Court's docket next term. So far, two- and three-judge panels on four federal appeals courts have weighed in, granting some injunctions while denying others.