Maryland Sen. Ben Cardin helped author a provision in the Wall Street financial reform bill passed in 2010 that makes oil, mining and gas companies disclose payments they make to host governments in countries where they do business.
The Securities and Exchange Commission wrote rules to enforce the law last year, but the American Petroleum Institute sued to stop the SEC from enacting the law. Cardin argues companies are not allowed to impede the power laws like this that were passed by Congress and approved by the president.
Supporters like Ian Gary of Oxfam America are guardedly optimistic a court will side with them.
"We think we have the facts on our side and that the oil industries arguments are frivolous," says Gary. "But you can't predict what's going to happen in a court case."
API has argued the law put US companies at a competitive disadvantage as compared to others than do not have to follow it.