U.S. Senate Republican leaders struggled Tuesday to keep alive their effort to overhaul the country's key health law, postponing a vote after an independent analysis concluded that 22 million people would lose their insurance over the next decade if their proposal was adopted. Senate Majority Leader Mitch McConnell of Kentucky told his Republican colleagues he would delay a planned vote this week until after the weeklong recess centered on the July Fourth national holiday commemorating the country's 18th-century independence from England. Several Republican lawmakers had said they would not even vote to start debate on the party's proposal, which forced McConnell to drop his plan to hold a final vote by week's end before lawmakers left Washington for the holiday. "Legislation of this complexity always takes longer than anyone wants," McConnell said after agreeing to the delay. "We think we're going to get legislation that's better than the status quo." However, Senator Charles Schumer of New York, the leader of the minority Democrats, said, "The Republican bill is rotten to the core." He said Democrats would work with Republicans to improve the existing law if they abandoned their effort to cut health care spending for the poor and curb taxes on the wealthy. Some Republican opponents of the health law changes said the plan would cost too many poor Americans their insurance, while others thought the changes did not go far enough in overturning key provisions of the seven-year-old law championed by former President Barack Obama and popularly known as Obamacare. Only two votes to spare Senate Republicans hold a 52-48 majority in the Senate. With all Democrats opposed to repealing the existing law, Republicans can lose only two supporters in order to pass their proposal, with Vice President Mike Pence prepared to cast the deciding vote in the event of a 50-50 deadlock. But at least four Republicans said they would vote against even starting debate on the plan, while others had also expressed reservations about the proposal, leaving their votes in doubt. One of the opponents, Senator Susan Collins of the northeastern state of Maine, said proposed funding cuts of nearly $800 billion in Medicaid, the government's health care program for the poor, "hurt the most vulnerable Americans" and that access to health care in rural parts of her state would be threatened. Another opponent, Senator Rand Paul of Kentucky, said it was worse to "pass a bad bill than to pass no bill." CBO estimates Opposition to the Republican overhaul grew Monday after the independent, nonpartisan Congressional Budget Office said 22 million people would lose their health insurance over the next decade under the Republican plan, only a million fewer than the estimate made by the CBO for the bill the House of Representatives narrowly approved last month. The CBO said Monday that the Senate bill would reduce the federal deficit by $321 billion by 2026, compared with a $119 billion reduction for the House version. The White House criticized the CBO as having a "history of inaccuracy" in estimating the effects of health care laws. It further reiterated that President Donald Trump was committed to repealing and replacing Obamacare, saying the program "has failed the American people for far too long." No mandatory purchases Both the House and Senate proposals would end the requirement that Americans buy health insurance or pay a fine. They would phase out subsidies to help lower-income people buy insurance, curb taxes on the wealthy and cut hundreds of billions of dollars in funding over the next several years for the government's health care program for the poor and disabled. If the Senate eventually approves its version of an overhaul, either the House would have to pass the same bill or reconcile its version with the Senate's before Trump could sign it into law.