By Matthew Bigg
ATLANTA (Reuters) - Lawyers for President Barack Obama will on Wednesday seek to stave off the biggest legal challenge yet to healthcare reform, his signature domestic policy achievement.
The administration will present oral arguments as it appeals a ruling by a Florida judge who declared the Affordable Care Act unconstitutional, backing claims by 26 U.S. states that are seeking repeal.
A three-judge panel at the 11th Circuit Court of Appeals in Atlanta will hear oral arguments by both sides. While a Virginia appeals court heard a similar case in May, this case is significant because of the number of states backing it.
No ruling is expected for months and legal experts expect an appeal to the Supreme Court, regardless of which side wins.
The law aims to increase access to healthcare and slow the growth in costs. The White House views it as a cornerstone of Obama's presidency. Republicans say it will send costs soaring and represents intrusive government power especially because it mandates all individuals to buy health insurance.
They plan to make their campaign for repeal a pillar of efforts to defeat Obama at presidential elections in 2012.
"Opponents of reform claim that the law's individual responsibility provision exceeds Congress' power to regulate interstate commerce because it penalizes 'inactivity.' They are wrong," the White House said on its blog on Tuesday.
"Individuals who choose to go without health insurance are actively making an economic decision that affects all of us," it said of the provision to fine Americans who do not buy insurance, which comes into effect in 2014.
The 2010 law also allows young people to remain on their parents' health insurance into their twenties and prevents insurers from denying coverage for preexisting medical conditions.
Florida District Judge Roger Vinson ruled in January the entire law "must be declared void" because its requirement to buy insurance is unconstitutional, but put the ruling on hold pending appeal.
"The nation needs healthcare reform that's pursued constitutionally and in a way that does not harm our economy and our taxpayers," Florida Attorney General Pam Bondi said in a statement.
Chief Judge Joel Dubina, Judge Frank Hull and Judge Stanley Marcus will hear the appeal. Analysts will watch their questions closely for clues as to how they might rule.
Dubina was appointed by President George H. W. Bush, a Republican, while the other two were appointed by President Bill Clinton, a Democrat.
Senior administration lawyer Neal Katyal will argue for the government, while former Solicitor General Paul Clement will present Florida's case.
The case is State of Florida et al v. U.S. Department of Health and Human Services et al. Its number is 11-11021.
(Editing by Eric Walsh)