California lawyer and atheist Michael Newdow has again petitioned the U.S. Supreme Court to do away with the nation's motto "In God We Trust."
On Tuesday, Newdow said the presence of the phrase on the nation's official currency violates the separation of church and state.
"Devout atheists are forced to choose between not using what is often the only available legal tender and committing what they consider blasphemy," Newdow argued in his court brief.
This latest challenge is just one of several First Amendment arguments Newdow has pending before the high court.
He is also challenging the phrase "So help me God" in the presidential oath as well as the pledge of allegiance.
Newdow acknowledged on Wednesday that his petitions are unlikely to be successful, The Kansas City Star reported.
"I think it is a sheer cliff with any court comprised of justices who are not atheists themselves," Newdow said in an e-mail.
"I think they would rather avoid the political fallout than do what they are paid to do and uphold the rights of this disenfranchised minority; i.e., atheists," he added.