TEHRAN -- Iranian President Mahmud Ahmadinejad was expected to address a large gathering at Tehrans Azadi Stadium, which can seat more than 100,000 people.
The presidents office says the April 18 event is meant to thank an organization that facilitated cultural activities and travel inside Iran during the two-week Norouz holidays marking the Iranian New Year.
Ahmadinejads critics have accused the president of seeking to use the occasion to influence the June 14 presidential election.
They say Ahmadinejad will use the event to informally launch the presidential candidacy of his close aide, Esfandiari Rahim Mashaei.
Many believe Ahmadinejad is grooming Mashaei as his successor.
Ahmadinejads second term in office ends in four months, and the countrys constitution bars him from running for a third term.