Healthcare reform is President Barack Obama's main domestic priority
US senators have passed the second of three procedural votes on a major healthcare reform bill.
Democrats collected the 60 votes needed to halt debate on the bill, putting the legislation on course to face a final vote on Christmas Eve.
President Barack Obama has set health reform as a key domestic objective for his first term.
Democratic leader Harry Reid appealed to senators to avoid personal attacks, describing the atmosphere as tense.
"Let's just all try to get along. Let's try to work through this," Mr Reid said.
Final passage of the bill is now scheduled for Christmas eve at 1300 GMT after Mr Reid and his Republican counterpart Mitch McConnell agreed to shorten the 30-hour long debating period which normally precedes the final vote.
Before that though, the bill will have to clear one more 60-vote hurdle on Wednesday.
Mr Obama has said he will delay leaving for his holiday if necessary to ensure he is present to solve any last-minute problems.
If approved, the legislation, which aims to cover 31 million uninsured Americans, could lead to the biggest change in US healthcare in decades.
SENATE HEALTHCARE BILL: NEXT STEPS
Wednesday 23 December: vote to approve substitute amendment (simple majority needed)
Wednesday 23 December: procedural vote on the bill as a whole (60 votes needed)
Thursday 24 December: vote on the final bill (simple majority needed)
2010: Senate and House versions of the bill to be reconciled
Monday's vote, when senators split 60 to 40 along party lines, was a crucial victory for the president.
He said the Senate had shown it could "stand up to the special interests" and that the bill would make a "tremendous difference for families, for seniors, for businesses and for the country as a whole".
Under the Senate bill, most Americans would have to have health insurance.
Private insurers would be banned from refusing to provide insurance because applicants had pre-existing medical conditions.
If passed, the Senate bill would have to be reconciled with a more expansive one passed last month by the House of Representatives.
Key differences in the House version include a government-run health insurance plan, or public option, and how to pay for the reform.