Prime minister Binali Yildirim made a speech at an event in Istanbul.
"The leader of the main opposition party [Kemal Kilicdaroglu] is starring in the attacks, while the screenwriter is FETO, and the producer is the global political engineers. The plot is bringing Turkey to its knees," Yildirim said.
On Tuesday, Kilicdaroglu, in a speech to party lawmakers, presented documents he alleged were evidence of his claims that relatives of President Recep Tayyip Erdogan had money abroad.
Turkey’s ruling Justice and Development (AK) Party accused the main opposition leader of telling "lies", calling on him to present the documents in court to prove the claims.
Erdogan has rejected the allegations and vowed to resign if they were proved.
Yildirim said those who gave documents to Kilicdaroglu's hands wanted to do "character assassination" of Erdogan.
"You know that you are unable to compete with him [Erdogan], [so] now you are trying to attack his family and relatives," Yildirim said referring to Kilicdaroglu.
Yildirim said Kilicdaroglu should share every document that he has.
"You fell under FETO's spell and you are drifting with the tide of FETO. You will be remembered in Turkey's political history as an experienced maligner. [...] You have turned Turkish Republic's founder Gazi Mustafa Kemal Ataturk's party to the backyard of global colonial powers," Yildirim said.
Yildirim said Kilicdaroglu lost nine elections since he became CHP leader in 2009 and promised each time to resign if he loses the election.
"Did you see him resigning? Election ended, everything ended. Then he forgot everything. You should be honest first," Yildirim added.