In blistering criticism of Erdogan, the spokesman for the main opposition Republican People's Party Bulent Tezcan attacked what he said was a "fearful atmosphere" in Turkey, Reuters reported.
Erdogan's lawyer Huseyin Aydin said on Twitter: "We have filed a legal petition concerning Bulent Tezcan with the Ankara chief prosecutor's office for the crime of insulting the president." Aydin also posted photos of the petition.
Tezcan's comments prompted a swift backlash from Erdogan's office and lawmakers from his ruling AK Party, with Erdogan's spokesman Ibrahim Kalin saying his "hate speech is an example of disgrace for the main opposition".
Insulting the president is a crime punishable by up to four years in prison in Turkey.