BEIRUT, Lebanon  In an implicit rebuke to Iran’s ruling elite, a conservative presidential candidate warned Sunday that the political and social rifts opened by the disputed June 12 vote and subsequent crackdown could lead to the nation’s “disintegration” if they were not resolved soon.

The candidate, Mohsen Rezai, made his warning in a long statement about the election and its bloody aftermath, in which he called for reconciliation and spoke about the danger of “imprisoning” the legacy of the Islamic Revolution in divisive and shortsighted politics. The statement was posted on his Web site.

Although his message was largely nonpartisan, Mr. Rezai hinted that the government response after the election had been unfair, and he urged protesters to continue their work in legal and nonviolent channels.

Like the three other opposition candidates, Mr. Rezai, a former chief of the elite Revolutionary Guards, initially said he believed that President Mahmoud Ahmadinejad’s landslide victory involved ballot-rigging. Mr. Rezai later withdrew his legal challenge to the results, citing the need for unity.