Iran's former nuclear negotiator accused hardline President Mahmoud Ahmadinejad of distorting facts about the country's nuclear past to make himself look like a hero and win votes for next week's election. Hasan Rowhani, who negotiated a 2003 deal with Europe to suspend Iran's controversial uranium enrichment program, also called Ahmadinejad a "demagogue" for claiming his administration was behind all of Iran's nuclear success. In comments posted Friday on a Web site belonging to Rowhani's think tank, The Center for Strategic Research, the ex-negotiator said Ahmadinejad's hard-line policies harmed Iran's reputation and led to three round of UN sanctions against Iran. "Is it dignity that economic sanctions are imposed against Iran?" Rowhani asked. The criticism is part of verbal dueling ahead of the June 12 presidential election, in which Ahmadinejad faces a tough challenge from three other contenders - including two reformists - for the country's top job. Ahmadinejad said reformists humiliated Iran because they halted all the nuclear work under the 2003 deal. The reformists say this is not true and that only uranium enrichment stopped. They say it was a "temporary" move that saved Iran from UN punishment, while allowing it to continue to develop other parts of its nuclear program. Ahmadinejad's campaign has touted Iran's nuclear progress in efforts to deflect criticism for the mismanagement of the country's economy, something his opponents have honed in on. Rowhani is a moderate with close ties to former president, Hashemi Rafsanjani, a top cleric who held the presidency 1989-97. Ahmadinejad recently denounced the 2003 deal under his predecessor Mohammad Khatami as "disgraceful." After coming to power in 2005, Ahmadinejad resumed uranium enrichment, which the US and its allies fear mask nuclear arms making - a charge Teheran denies. Uranium enrichment can produce fuel for a nuclear reactor or material for a bomb. "I don't know why the gentleman insists on distorting facts ... for the sake of obtaining a few more votes" or making himself look the hero, Rowhani said, referring to Ahmadinejad. "Harsh words won't help win votes," he added. "Demagoguery no longer works." Rowhani defended the 2003 suspension as "wise" because it came amid intense pressure by the UN nuclear watchdog agency and fears that Washington could move against Teheran after toppling the extremist Taliban regime in Afghanistan and former Iraqi dictator Saddam Hussein. Khatami, who ran the country between 1997-2005, has already demanded an apology from Ahmadinejad for calling the 2003 deal disgraceful and for saying Khatami played into "colonial policies" designed by Iran's enemies bent on "finishing" the Iranian nation. Neither Katami nor Rafsanjani are running in the election, but their criticism of Ahmadinejad has added to the president's troubles during the campaign. Ahmadinejad's chief reformist rivals are: Mir Hossein Mousavi, a former prime minister in 80s, and Mahdi Karroubi, a former parliamentary speaker. The sole conservative challenger to Ahmadinejad is Mohsen Rezaei, a former Revolutionary Guards commander.