Two losing contenders in Iran''s presidential election denounced the result on Wednesday in clear defiance of Supreme Leader Ayatollah Ali Khamenei, saying Mahmoud Ahmadinejad''s next cabinet would be illegitimate.

Moderate former prime minister Mirhossein Mousavi and reformist cleric Mehdi Karoubi unleashed fierce attacks on the outcome of the June 12 vote that returned Ahmadinejad to power as president for a second term.

Pro-reform ex-president Mohammad Khatami also criticized the vote and the mass arrests of demonstrators that followed, declaring in a hard-hitting statement: "Oppressing people will not help end the protests."

Although hardliners have appeared to be in the driving seat since security forces overcame street protests that erupted in the days after the poll, Mousavi and Karoubi have not yielded.

Both men issued statements on their websites describing Ahmadinejad''s future government as "illegitimate" -- even though Khamenei, the Islamic Republic''s ultimate arbiter, has upheld the result and thrown his weight behind the president.

"It is our historic responsibility to continue our protests and not to abandon our efforts to preserve the nation''s rights," Mousavi wrote, urging the release of "children of the revolution" -- meaning scores of reformist political figures rounded up during Iran''s gravest unrest since the shah fell in 1979.