Sen. Roy Blunt, R-Mo. (File photo)

Members of the Senate today voted 51-48 to block an effort to let employers opt out of some Patient Protection and Affordable Care Act (PPACA) coverage requirements for reasons of conscience.

Senators voted mostly along party lines.

Sen. Olympia Snowe, R-Maine, who earlier this week announced plans to retire from the Senate, voted with the Democrats.

The two independents in the Senate, Joseph Lieberman of Connecticut and Bernard Sanders of Vermont, also voted with the Democrats.

The Democrats who voted with the Republicans, in support of the PPACA conscience exemption measure, are Robert Casey Jr. of Pennsylvania, Joseph Manchin of West Virginia, and Ben Nelson of Nebraska.

Sen. Roy Blunt, R-Mo., introduced the measure, Blunt Amendment Number 1520 to S. 1813, the Moving Ahead for Progress in the 21st Century Act (MAP-21) bill.

The Senate was voting on a motion to table the amendment.

Blunt needed a majority vote to get the amendment to come up for consideration on the Senate floor.

U.S. Health and Human Services Secretary Kathleen Sebelius triggered the showdown, by ruling that the basic preventive services package that health insurers and health plans offer should include coverage for contraceptive services and devices. Sebelius later ruled that employers need not offer contraceptive services benefits but that insurers must provide the benefits for group plan members if the members’ employers do not.

Blunt and other Republicans have accused Sebelius of infringing on employers’ freedom of conscience; Sebelius and supporters of her position point to analyses suggesting that providing broader access to contraception benefits could reduce overall health care spending.

Snowe said in an interview on MSNBC that she would consider voting for another contraception preventive benefits mandate measure.

“With respect to the Blunt amendment, I think it’s much broader than I could  support,” Snowe said in the interview. ”I think we should have focused on the issue of contraceptives, and whether or not it should be included in a health insurance plan.”