An influential former Iranian prime minister said Tuesday that he will run in the upcoming presidential election, posing what could be a serious pro-reform challenge to the hard-line president, Mahmoud Ahmadinejad. Mir Hossein Mousavi, who was premiere during the 1980s Iran-Iraq war, is seen by many as a strong candidate in the June election because he was once a hard-liner and could siphon votes away from Ahmadinejad's base. He announced his intention to run in a statement made available to The Associated Press. But Mousavi may face a challenge for reformist votes since there are two other strong candidates from his camp running for election: former President Mohammad Khatami and former parliament speaker Mahdi Karroubi. Some analysts have speculated that the reformists are fielding several strong candidates during the initial stages of the campaign as a way to diffuse hard-line attacks, but will reduce the number to one shortly before the election to concentrate support.