The sharp attacks by the candidate, Mir Hussein Moussavi, came during a fierce 90-minute debate with Mr. Ahmadinejad that was broadcast throughout Iran. The two candidates clashed repeatedly during the one-on-one debate, with each accusing the other of radicalism and undercutting the country’s interest. Mr. Moussavi, a former prime minister whose moderate views have won him support from other reformers in Iran, including former President Mohammad Khatami, has positioned himself as the strongest challenger to Mr. Ahmadinejad. Support from the Islamic authorities for the president, who is a religious conservative, appears to have weakened, and he is now widely criticized for Iran’s economic malaise.
