The US Supreme Court will hear evidence challenging President Barack Obama's health care reform -- which has come under fire from Republicans -- over three days in March, a spokeswoman said Monday.
A ruling against the landmark legislation, The Affordable Care Act, would be a major blow for Obama and his Democratic Party as he battles to win a second term in November 2012 elections.
A spokeswoman for the Supreme Court said oral evidence would be taken on March 26, 27 and 28 from challengers of the reform.
Opponents say the most controversial feature of the law, a mandate that says individuals must buy health insurance or face a tax penalty, violates rights enshrined under the US Constitution.
A challenge on the individual mandate, from the state of Florida, will be heard on March 27 and two hours have been set aside that day, according to schedules published on the Supreme Court website.
A second challenge to the law by 26 US states and small businesses that want to completely strike down Obama's reforms, will be given one hour on March 28.
The legislation, a key plank of Obama's 2008 White House campaign which passed into law amid much fanfare in 2010, was later taken up by the nation's top bench of nine judges.
Republican opponents argue that the government has no power to compel people to buy health insurance.
On November 8, a US appeals court upheld the constitutionality of Obama's health care overhaul, ruling that mandating people to buy health insurance or face a tax was not a violation of individual rights.
In August, a federal appeals court in Georgia ruled that the individual mandate exceeded the powers of Congress, but also said that the remainder of the health care law was within the bounds of the constitution.
Explore further: US appeals court hears arguments on health care law