During the 1980s Chen emerged as the main figure among the more hard-line opponents of reform.
That ruling was quickly seen as an administration-led attack on a hard-line opponent.
The vote could be a key test between so-called pragmatists and their hard-line opponents in the Islamic republic.
The movement has withstood major setbacks from its hard-line opponents inside the country, who control major security and judicial positions.
The move, which is likely to intensify the fight between reformers and their hard-line opponents, was unprecedented in the country's parliamentary history.
The West would blame his hard-line opponents, not him, for introducing coercive measures - as it had done so many times before.
Reformist lawmakers voiced strong criticism of hard-line opponents and vowed not to give in to measures that were meant to force them to resign.
In politics he assumed the position of hard-line opponent of any form of compromise with domestic opponents or the international community.
Waters, on the other hand, is seen as more of a hard-line opponent.
Mr. Khatami sharply attacked his hard-line opponents, accusing them of trying to cling to power at any price.