The battle for Iran's presidency intensified Monday, as reformers rallied around the candidacy of former president Ali Akbar Hashemi Rafsanjani, accusations of vote-rigging grew and three newspapers that published a candidate's letter critical of the election were shut down.

The scramble to support Rafsanjani, 70, a cleric and power player who has made many enemies during a quarter-century in Iran's political establishment, reflected concerns about the possible ascendance of Tehran Mayor Mahmoud Ahmadinejad, 49, the other candidate in Friday's runoff. Ahmadinejad is widely seen as the favorite of the clerical establishment because of his traditional views and the religious tenor of his campaign.

Three rival campaigns charged that Ahmadinejad's unexpectedly strong showing, announced at 19.5 percent of last Friday's vote, was orchestrated by Iran's military and volunteer militia force in concert with the Guardian Council, a body controlled by hard-line clerics that was responsible for counting the votes.

On Monday, Mehdi Karrubi, the moderate cleric who finished less than 1 percentage point behind Ahmadinejad, protested the election by resigning from the Expediency Council, which like the Guardian Council is among the three appointive bodies with powers greater than those of Iran's elected government. He also quit his post as adviser to Ayatollah Ali Khamenei, who as supreme leader holds ultimate authority in the theocracy.

"Had the Guardian Council had the authority, it would have ordered Ahmadinejad to be elected without even considering the votes," said Karrubi, who has often served as a liaison between reformers and hard-liners.

He blamed the Revolutionary Guard Corps and the basij, a volunteer militia supported by the government and often deployed against student protesters, for interfering in the vote.

"My popular votes were increasing in spite of the fact that certain sections of the Revolutionary Guards and basij forces -- by paying money to religious centers and gathering places, and their unusual presence in polls -- were illegally publicizing another candidate," Karrubi wrote in an open letter to Khamenei. "I had told you about this before the election day and I am informed that same warning was given to you by the interior, intelligence and justice ministers."

The state's response came in two forms. The Guardian Council announced a quick recount of 100 random ballot boxes in four provinces. Within hours, it declared the election fair.

Also, the three newspapers that quoted Karrubi's letter Monday morning were closed, joining a list of more than 100 publications shuttered by hard-liners in Iran's judiciary.

"We advise Mr. Karrubi to revise his statement," said a spokesman for the Revolutionary Guard, which was formed to safeguard the Islamic republic in the days after the 1979 revolution, but in recent years has been at the vanguard of hard-liners' attempts to dominate Iran's elective offices. "There are certain red lines nobody should cross, including Mr. Karrubi."

About 70 former guard members serve in the parliament elected last year after the Guardian Council barred more than 800 reformist candidates from the ballot.

The council rejected more than 1,000 presidential hopefuls this year; four of the eight candidates it approved were veteran guard commanders. Ahmadinejad also served in the basij.

An official with Ahmadinejad's campaign said the candidate was being demonized "to scare people away from him."

The official, who would identify himself only as Khaki, saying he was not authorized to speak for the candidate, asserted that voters were impressed with the mayor's low-key, bare-bones campaign, which stressed his humility and working-class background. The effort stood in contrast to the Western-style media blitzes of other candidates "taking no notice of their religious values," he said.

Ahmadinejad's "way of life is modeled on the prophet's," Khaki said in an hour-long interview, referring to the prophet Muhammad. He added that, as president, Ahmadinejad would install "a healthy Islamic administration" distinct from the corruption associated with Rafsanjani's two terms in 1989-97.

Before Friday, many reformers were similarly critical of Rafsanjani, who finished with an announced tally of 21 percent of the vote. But this week supporters of the outgoing president, Mohammad Khatami, rushed to answer Rafsanjani's call to "prevent all extremism."

Reformist parties including the Executives of Construction Party, the Islamic Revolution Mujaheddin Organization and the Islamic Iran Participation Front threw their support behind the "pragmatic conservative," as Rafsanjani has cast himself.

"Despite all the 'ifs' and 'buts' of the presidential election and broad illegal interference of military forces, we would like to warn everybody about the immediate risk and danger of reactionary forces and fascism, and invite them to participate in the next Friday's election," the Participation Front said in a statement. "We invite all our fellow countrymen to vote for Hashemi and avoid the disaster, in which all of us would be nothing but mere victims."

"The warning bell has sounded for our fledgling democracy," said a statement from reformist candidate Mostafa Moin, who finished fifth and joined Karrubi and Rafsanjani in complaining of fraud.

"Certain reformists refer to the footsteps of fascism being heard," said Mohammad Atrianfar, a senior official in the Rafsanjani campaign. "The risk of violence by extremists has formed a consensus around Mr. Rafsanjani."

Atrianfar said Rafsanjani's campaign was considering asking that Friday's runoff be delayed a week so complaints of fraud could be investigated thoroughly and so the campaign would have time to regroup. But he also expressed confidence that the former president would prevail by drawing support from like-minded candidates who failed to make the runoff but accounted for about 17 million of the 29 million votes cast.

"It's a fight between backwardness and development," he said. "With the presidency of Ahmadinejad, our country would surely collapse."

Staff members gather at Tehran's Eqbal newspaper, where publication was suspended at the order of the judiciary.