Missing Iran leader Ahmadinejad under pressure from MPs
Powerful MPs in Iran have called for a closed debate on President Mahmoud Ahmadinejad's apparent boycott of his official duties.
The president has not been seen at his office for days, missing two cabinet meetings and cancelling a visit to the holy city of Qom.
Iran's Supreme Leader, Ayatollah Khamenei, recently re-instated a cabinet minister he had pushed out.
Analysts believe an internal power struggle may be under way.
One conservative MP, Gholamreza Mesbahimoghadam, told parliament on Saturday: "Let the Majlis [parliament] do its legal job."
This was a tacit call for Mr Ahmadinejad's impeachment, the BBC's Mohsen Asgari in Tehran says.
Some MPs have accused Mr Ahmadinejad's supporters of putting pressure on ministers to sign a letter backing president against the supreme leader.
Many conservatives believe that Vice-President Esfandiar Rahim Mashaie is the root cause of the problem.
"Today Mashaie is the actual president," Mojtaba Zolnoor, a senior cleric, said. "I hope that God will rid the president from the evil of this person."
Mr Mashaie, who is rumoured to be the president's choice to succeed him in 2013, has been working with Mr Ahmadinejad for 25 years.
He is bitterly condemned by conservatives for his nationalistic views and his liberalism on cultural and social issues.
However, Mr Ahmadinejad's followers believe that some are plotting against the president.
Simmering tensions between supporters of the two men came to a head on 17 April, when Intelligence Minister Heidar Moslehi was forced to resign, our correspondent adds.
Mr Moslehi was promptly re-instated by the supreme leader.
Under the constitution, the president is in charge of appointing ministers - who then need to be approved by parliament.
Nearly 300 MPs urged Mr Ahmadinejad, in a letter, to respect Ayatollah Khamenei's decision.
While the president has not been seen at government meetings, Mr Moslehi attended a cabinet meeting last Sunday, the Associated Press news agency reports.
One unnamed reformist politician told the BBC that a "game of chicken" had begun.
"I hope one side yields at the end - otherwise it will move the country toward unprecedented instability that will certainly suck the current Arab uprisings into the country," the politician added.