Thirty-two million Americans would lose their health insurance by 2026 under a US Senate plan to repeal Obamacare without providing a replacement, the Congressional Budget Office has said.
The CBO estimated the number of uninsured would rise by 17 million next year alone if the Affordable Care Act were to be scratched without a new healthcare plan.
Meanwhile, US President Donald Trump has criticised Senate Republicans for failing to reach agreement on repealing or overhauling Obamacare, demanding they not leave Washington for a planned August recess until they can find common ground on healthcare.
Mr Trump's call to action on Obamacare, at a White House lunch with 49 senators, was in sharp contrast to his hands-off approach to the Senate's work over the past few weeks.
Yesterday, after the seven-year Republican quest to repeal and replace former president Barack Obama's signature healthcare law collapsed in the Senate, he suggested he would be fine with letting Obamacare fail.
But at the lunch he told the senators he wanted more than a straight repeal and also wanted to replace Obamacare.
"We're close. We're very close," Mr Trump said at the start of the meeting.
He demanded that politicians keep their campaign promises and find a new approach to healthcare.
"For seven years you promised the American people you would repeal Obamacare. People are hurting and, frankly, inaction is not an option," Mr Trump told his fellow Republicans.
"Any senator who votes against starting debate is really telling America that you're fine with Obamacare."
"We can repeal, but we should repeal and replace and we shouldn't leave town until this is complete," he said.
Senate Majority Leader Mitch McConnell said he will go ahead with a vote early next week to begin debate on a repeal of the Affordable Care Act, popularly known as Obamacare, despite indications it will fail after the defections of at least three Republican senators.
