Iran's former reformist president demands Mahmoud Ahmadinejad apologize for calling his predecessor's move on the country's nuclear program "disgraceful."
Ahmadinejad recently blasted former president, Mohammad Khatami, for his 2003 deal with Europe to suspend uranium enrichment.
After taking office in mid 2005, Ahmadinejad resumed the controversial enrichment.
Khatami, who ran the country between 1997-2005, says Ahmadinejad should apologize for the remark.
The rhetoric is part of verbal campaign dueling ahead of the June 12 presidential election.
Ahmadinejad faces a tough challenge by three contenders for the top job, including leading reformist challenger Mir Hossein Mousavi. Khatami is backing Moussavi.