Updated

A federal judge on Friday blocked a new Missouri law that requires insurers to exclude birth control coverage for moral objectors, ruling that it conflicts with an insurance mandate under President Barack Obama's health care law.

The temporary restraining order halts the Missouri law just three months after the Republican-led Legislature enacted it by overriding Democratic Gov. Jay Nixon's veto.

The state law requires insurers to issue policies without contraception coverage if it runs contrary to the religious or moral beliefs of an individual or employer. The law appeared to be the first in the nation to directly rebut an Obama administration policy that requires insurers to cover birth control at no additional cost to women.

U.S. District Judge Audry Fleissig wrote in her order that there "appears to be an irreconcilable conflict" between the state and federal laws that puts insurance companies in an awkward position. If they were to comply with Missouri's law, insurers could be subject to federal penalties for not abiding by the contraception mandate. Yet insurers also could face financial penalties from the state insurance department for failing to follow the Missouri law.

"Insurers are placed in an untenable position as they cannot comply with both statues at the same time," Fleissig wrote, noting that the U.S. Constitution gives preference to federal laws over state laws.

State Sen. John Lamping, a Republican from suburban St. Louis who sponsored the law, said he was neither surprised nor discouraged by the court ruling.

"That's the logical thing that I thought would ultimately occur post-election," when Obama defeated Republican presidential challenger Mitt Romney, he said. "Clearly, this is an issue at the federal level that remains unresolved."

Lamping noted that federal courts have issued conflicting rulings on challenges to the Obama administration directive that contraception coverage be included as part of the basic preventative services required by the 2010 health care law. If the federal requirement ultimately is struck down by a higher court -- or Congress someday changes the contraception mandate -- then the Missouri law likely would be upheld, he said.

The challenge to Missouri's law was brought by the Missouri Insurance Coalition, which represents the insurance industry. The court ruling said the state insurance department already had issued a cease and desist order against at least one of the insurers in the coalition, alleging it was "engaging in fraud" by violating Missouri's contraception-exemption law.

Friday's restraining order says the state insurance department may approve policies with a contraception exemption but cannot reject insurance policies because they lack an exemption for moral and religious objectors. The judge said a hearing for a preliminary injunction would be set later.