The Senate health committee narrowly passed (13-10) a measure to provide 50 million uninsured Americans with health care coverage on Wednesday.

The new legislation is a top priority for the Obama camp and would amount to biggest change in U.S. social policy in more than 40 years, according to the New York Times.

The measure failed to garner Republican support, despite three weeks of committee sessions devoted to hammering out its details. Conservatives argue the package gives the government too much responsibility and, with an estimated $1 trillion price tag over 10 years, is too expensive.

“This bill gets an F”, said Senator Michael Enzi (R-WY), a member of the health committee. “The bill is anything but affordable”.

The new legislation would mandate insurance coverage for every U.S. citizen. In the absence of employer-sponsored benefits, the federal government would offer financial assistance and discounts on a public insurance plan.

Employers who don't offer health care benefits would pay a fee to the federal government to help offset the costs of the measure. The finance committee, which is expected to introduce a separate approach to the health care overhaul by the end of the month, might also recommend a government-imposed fine on private health insurance companies.

Senate conservatives hope the measure advanced by the finance committee, which will outline funding schemes for its proposals, will yield more bipartisan support.

The approved overhaul is expected to make coverage more accessible and eliminate inequalities in the current system. Senator Christopher Dodd (D-CO), who heads up the Senate Health, Education, Labor and Pensions committee, said the new system should prohibit insurance companies from denying coverage based on pre-existing conditions and eliminate annual and lifetime caps on benefits.

“If you don’t have health insurance, this bill is for you”, he said. “It guarantees that you’ll be able to find an insurance plan that works for you, including a public health insurance option if you want it”.

Obama is pushing to get the measure through the House and the Senate before the August recess, but reaching consensus anytime soon will be difficult.

Obama's campaign organization sponsored a series of 30-second television ads featuring ordinary citizens discussing their complaints with the status of health care in the U.S. The ads premiered on national cable TV channels on Wednesday and will run on local stations in select cities for a two-week period.