Millions of people will lose their health insurance under Republican plans to repeal and replace Obamacare, according to an independent analysis.
The non-partisan Congressional Budget Office (CBO) said an extra 14 million people would be living without coverage in 2018, rising to an additional 24 million by 2026.
The figures are a blow to the Republican leadership which faces a tough battle to get its bill through Congress and to Donald Trump, who promised insurance for everybody before he was elected.
Two Congressional committees have approved the legislation since it was unveiled a week ago. However, conservatives say the American Health Care Act does not go far enough in removing government interference from health care, while some moderate Republicans fear a backlash from voters who will no longer be able to afford insurance.
Medical providers, including doctors and hospitals, have also expressed reservations.
Mr Trump tried to rally support for the proposals on Monday during a White House “listening meeting” with people affected.
“The House bill to repeal and replace Obamacare will provide you and your fellow citizens with more choices - far more choices - at lower cost,” he said.
Throughout the campaign, he promised a bigger and better system for Americans as part of his populist programme directed at blue collar workers.
The proposals remove a legal requirement for all citizens to buy insurance and replaces federal funding for subsidised services with a system of tax credits.
Overall, the CBO projected that 52 million people would be uninsured by 2026 if the bill became law, compared to 28 million if Barack Obama's signature law remained in force.
A change in regulations, it found, would mean fewer employers offering coverage to staff forcing them on to the individual market.
At the same time, the changes would save the government billions of dollars in spending, reduing the deficit by $337 billion ($276 billion) over 10 years.
Mr Trump's Health and Human Services Secretary disputed the forecast. Tom Price said: “We believe that the plan that we’re putting in place is going to insure more individuals than currently are insured. So we think that CBO simply has it wrong."