WASHINGTON - Republican presidential candidate Mitt Romney on Wednesday contradicted his campaign's stance on a key part of President Barack Obama's healthcare law, saying its individual insurance mandate amounts to a tax rather than a penalty.

A Romney campaign aide said on Monday that the former Massachusetts governor viewed it as a penalty, a politically sensitive distinction among voters opposed to higher taxes. In reversing course, Romney cited the Supreme Court decision last week.

"Well, the Supreme Court has the final word and their final word is that Obamacare is a tax," Romney said in a CBS television interview. "So it's a tax. They decided it was constitutional. So it is a tax and it's constitutional."

Obama's campaign accused Romney of contradicting both his staff and himself.

When the Supreme Court upheld the healthcare law as constitutional last week, it also declared that the fee charged to most Americans who refuse to buy health insurance amounted to a tax - and not a penalty, as Obama has called it.

Please LIKE our Facebook page - it makes us stronger