(Reuters) - The U.S. Supreme Court on Tuesday denied Ohio's request to curtail early voting in the state leading up to the Nov. 6 presidential election.

Ohio, critical to the election hopes of Democratic President Barack Obama and Republican challenger Mitt Romney, began early in-person voting earlier this month but planned to cut it off on Nov. 2, the Friday before the election, except for members of the military.

Earlier this month, the 6th U.S. Circuit Court of Appeals upheld a U.S. District Court order that reinstated early voting in the final days before the election. The state had appealed that ruling to the Supreme Court.