TEHRAN: Iran's former premier Mir Hossein Mousavi accused hardline President Mahmoud Ahmadinejad of "undermining" the Islamic republic's dignity during his four-year term, in a television debate on Wednesday ahead of next week's presidential poll.

Ahmadinejad's government "has undermined the dignity of our nation," said Mousavi who is considered the conservative president's main challenger in the June 12 election

"It has inflicted heavy damages on us and created tension with other countries," said Mousavi, a moderate.

The "mismanagement" of the country by Ahmadinejad's government forced him to enter the presidential race, Mousavi said in the debate aired by the English-language station Press TV.

He charged that Ahmadinejad's foreign policy suffers from "adventurism, instability, exhibitionism and extremism."

Mousavi, who was Iran's last prime minister before the post was scrapped in 1989, is seeking a comeback after two decades of political wilderness.

Ahmadinejad who opened the debate said he and his government have been facing sustained "attacks" from Mousavi and his supporters, like former president Akbar Hashemi Rafsanjani and reformist two-time president Mohammad Khatami.

"They said in six months this government will fall apart... they tried to crush this government," said Ahmadinejad who is seeking a second term in office.

The incumbent president said that the the election was not a race between four candidates but one that is pitting "three people against one," he said referring to Rafsanjani, Khatami and Mousavi.

"It is all against one person," he said.

Former parliamentary speaker Mehdi Karroubi and the former head of elite Revolutionary Guards Corps, Mohsen Rezai, are also in the race for the presidency.