A federal judge in the US state of Virginia has ruled against a key part of the Obama administration's law on healthcare reform.
The decision by US District Judge Henry Hudson is the first finding against the law passed in March.
He backed the state of Virginia's argument that the law's requirement that Americans purchase healthcare or face a fine was unconstitutional.
Other lawsuits are pending, but the US Supreme Court will have the final word.
The judge wrote in a 42-page decision that the disputed provision was "neither within the letter nor the spirit of the Constitution".
But he declined to invalidate the entire law, in what correspondents say was a small victory for Barack Obama.
The law on healthcare reform has become a centrepiece of Mr Obama's presidency.
It aims to extend health insurance to millions of Americans who lack it - partly by requiring the mostly young, healthy Americans who currently forgo insurance to purchase it.
Two judges have rejected other challenges to the law, including one in Virginia last month. BBC News
