RICHMOND, Va. (Dec. 13) -- A federal judge declared a key provision of the Obama administration's health care law unconstitutional Monday, siding with Virginia's attorney general in a dispute that both sides agree will ultimately be decided by the U.S. Supreme Court.

U.S. District Judge Henry E. Hudson is the first federal judge to strike down the law, which has been upheld by two other federal judges in Virginia and Michigan. Several other lawsuits have been dismissed and others are pending, including one filed by 20 other states in Florida.

Hudson rejected the government's argument that it has the power under the Constitution to require individuals to buy health insurance, a provision that was set to take effect in 2014.

"Of course, the same reasoning could apply to transportation, housing or nutritional decisions," Hudson wrote. "This broad definition of the economic activity subject to congressional regulation lacks logical limitation" and is unsupported by previous legal cases around the Commerce Clause of the Constitution.

There was no immediate comment from the White House.