Senator Hillary Clinton is challenging Barack Obama to agree to new Democratic primaries in Michigan and Florida.
Lawmakers in both states have been unable to reach an agreement on how to hold a re-vote.
The Clinton campaign accuses the Obama campaign of blocking the proposal for another vote, saying it was "wrong, and frankly un-American" not to have the two delegations seated at the Democratic National Convention.
"Senator Obama speaks passionately on the campaign trail about empowering the American people," the former first lady said. "Today I am asking him to match those words with actions."
Clinton was hoping that another primary would give her the chance to catch Obama in the delegate count before the convention. She trails him in convention delegates after primaries and caucuses in more than 40 states, and her chances of catching up are remote at best.
Second primary victories in Florida and Michigan would help narrow the delegate deficit.
And even if she fell short, victories over Obama would strengthen her argument that party leaders who attend the convention as superdelegates should consider a candidate's ability to win in key states in the fall election before they pick a candidate.
Now, it's up to the National Democratic Party to decide how to handle the two states' delegates.
Source: The Associated Press