(CNN)The Senate voted Wednesday night to overturn President Joe Biden's Covid-19 vaccine or testing mandate for private businesses with 100 or more employees. While it likely won't become law since its chances of getting a vote in the House are uncertain and Biden is certain to veto it, the effort demonstrates the bipartisan opposition in Congress to the federal government's vaccine mandate for large employers. The effort was led by Indiana Republican Sen. Mike Braun, and it needed just a simple majority of 51 votes to be approved by the chamber. The final vote was 52-48. Two Democrats, Sens. Jon Tester of Montana and Joe Manchin of West Virginia, joined their 50 GOP colleagues in voting to repeal the requirement. Biden back in September announced that he would be directing the Labor Department to require all businesses with 100 or more employees to mandate that their workers are either fully vaccinated or undergo weekly testing for Covid-19 and wear masks. The emergency rule was issued in November, prompting lawsuits from Republican-led states and private employers but also from liberal leaning unions. A federal appeals court last month temporarily blocked the Biden administration's vaccine rules, which had been planned to take effect on January 4. The multiple lawsuits against the mandate have since been consolidated and reassigned to a federal appeals court in Ohio, with many expecting the case to end up before the US Supreme Court. Senate Republicans last month filed their challenge to Biden's mandate under the Congressional Review Act, a legislative tool that allows Congress to roll back an executive branch rule. Braun and other Senate Republicans have argued that the vaccine mandate is an overstep of authority by the federal government and puts further strain on already struggling businesses, while also insisting that vaccines are a personal choice. Last week, as Congress faced a deadline to fund the government, a few Senate Republicans threatened to force a government shutdown unless they got a vote on an amendment that would prohibit the use of federal funding for Biden's Covid-19 vaccine mandates. The amendment, however, ultimately failed in a 50-48 vote. While he voted to extend government funding into February to avoid a shutdown, Manchin announced that he had signed on as a co-sponsor to the GOP resolution to overturn the vaccine requirement for businesses and "will strongly support" it. "I have long said we should incentivize, not penalize, private employers whose responsibility it is to protect their employees from Covid-19," the West Virginia Democrat said in a statement last week. Manchin isn't the only Democratic to express support for repealing the vaccine mandate. Explaining his opposition to the vaccine requirement, Tester said he "repeatedly heard concerns from Montana's small business and community leaders about the negative effect the private business vaccine mandate will have on their bottom lines and our state's economy." "That's why I intend to join a bipartisan majority of my colleagues in defending Montana jobs and small businesses against these burdensome regulations," he said in a statement Tuesday. Senate Minority Leader Mitch McConnell previously told Fox News that the Senate will vote on the resolution this week, adding that he thinks it will have a "decent chance of passing the Senate." Speaking to reporters on Tuesday, Senate Majority Leader Chuck Schumer slammed the Republicans-led challenge to the Covid-19 vaccine mandate as an "anti-science, anti-vaccine vote." "If their plans go into effect, Covid will linger longer and the chance of new variants and new more dangerous variants occurring increases," Schumer said on Capitol Hill. "It is anti-science, anti-common sense, it makes no sense." Many businesses, however, have voluntarily put in place safety measures early in the Covid-19 pandemic to protect their employees and customers, and are moving forward with Covid vaccine mandates regardless of whether the courts strike down or uphold the Biden administration's regulations.