CARACAS, Venezuela -- Prosecutors plan to bring corruption charges against a prominent opponent of Venezuelan President Hugo Chavez, claiming he misspent public funds by using them to launch an organization that has become one of the country's most popular political parties.

Opposition politician Leopoldo Lopez allegedly accepted donations from Venezuela's state-run oil company, Petroleos de Venezuela, in 1998, prosecutors said in a statement Saturday. Lopez was summoned to appear before prosecutors next month.

The donations were purportedly authorized by the politician's mother, Antonietta Mendoza de Lopez, when she was working for the state-run company known as PDVSA, its Spanish acronym. Lopez allegedly guided the donations to a close associate to form First Justice, an organization that later become one of the South American country's most popular political parties.

Lopez, a former Caracas district mayor, has denied any wrongdoing. In a message posted on the Twitter social networking site, Lopez said the accusations are politically motivated.

"Instead of persecuting criminals, they persecute dissidence!" he wrote.

Fellow opposition leaders, including Caracas Mayor Antonio Ledezma, defended Lopez.

"Our solidarity with Leopoldo Lopez," Ledezma said in a tweet. "He will not be alone!"