Cardinal Juan Sandoval, archbishop of Guadalajara, accused the court Tuesday of allowing itself to be "paid off," The Guadalajara Reporter said.
"I believe the judges don't come to these absurd conclusions that are against the sentiment of the Mexican people if the motives aren't very big," said Sandoval. "The great motive could be the money they receive."
Sandoval alleged the court's decision was part of a left-wing conspiracy masterminded by Mexico City Mayor Marcelo Ebrard, Spanish President Jose Luis Zapatero and liberal forces in Italy.
"Ebrard and international organizations paid off the ministers of the court with 'gifts,'" Sandoval alleged.
Ebrard responded by demanding a retraction of Sandoval's allegations and hinted he might file a defamation suit against the cardinal.
"It's very serious that a high-ranking member of a church tarnishes the Supreme Court," Ebrard said. "What this gentleman has said, he's going to have to prove."