The conservative hopeful, Rezaei, was even more critical on the administration's economic policies by reasoning on the high inflation and the high unemployment in the country.

Supporters of Iranian President Mahmoud Ahmadinejad attend his last presidential campaign in Tehran, capital of Iran, on June, 10, 2009, prior to the upcoming 10th presidential election slated for Friday. Four candidates of the election -- incumbent President Mahmoud Ahmadinejad, former Prime Minister Mir Hossein Mousavi, former Parliament Speaker Mehdi Karroubi and former Revolutionary Guards chief Mohsen Rezaei -- are racing for the presidency.[Zhang Ning/Xinhua]

The former Revolutionary Guards chief further accused the president of not using gifted experts as the consultant.  

The besieged president dismissed all these accusations as propaganda and ignorance of his achievements, especially in the areas of the country's nuclear program and missile advancements.

For his part, Ahmadinejad targeted the rivals by drawing upon their "economically corrupted supporters", their suspicious economic gains, their lack of expertise on the special jargons and their false predictions on the sensitive issues related to the country.

One of Ahmadinejad's fiercest attack on some rivals came on Wednesday when he was addressing thousands of his supporters in Tehran's Azadi Street where he referred to campaign strategies adopted by his rivals as the "methods utilized by Hitler".

He said, "the nation will say a bigger 'No' to the enemies, thus throwing them to the abyss of history" in the upcoming elections slated for June 12.

The recent overtures offered by the new US President Barack Obama were also used by Ahmadinejad to prove the success of his tough policies.

With divergent opinions on who would finally win the tense competition, local analysts have been cautious about the aftermath of such a rarity in the country's political scene.