Health premiums for individuals and families as well as small businesses would rise under the Senate's health bill, an insurer-backed study found Thursday.

A study of the merged Senate healthcare bill conducted by the research group Oliver Wyman and sponsored by the Blue Cross Blue Shield Association said that consumers would face significantly higher premiums under the Senate bill.

According to the study, individuals and families would face 54 percent higher premiums five years into the plan, while small businesses would face 20 percent higher rates.

The study also sought to undercut the Congressional Budget Office's (CBO) analysis of the Senate bill, saying it failed to take into account the amount of medical claims the currently-uninsured are likely to file.

Insurers have warned for months that the House and Senate health bills would result in higher costs for consumers, a charge on which Republicans have seized.

For their part, Democrats and President Barack Obama have blasted the insurer-backed studies, including today's, which White House Communications Director Dan Pfeiffer criticized in a blog post before the report was released.

"We’re closer than ever before to passing meaningful health insurance reform," Pfeiffer wrote. "And you can bet as we continue to make progress, the insurance industry will continue to try and distract and misinform because they know their very profitable status quo is in grave danger."

The Oliver Wyman report, Pfeiffer argued, failed to take into account the Senate bill's cost containment measures, and cherry-picks facts to work with.