One of Iran's most outspoken reformists, Vice President Mohammad Ali Abtahi, announced Monday he had submitted his resignation from the increasingly isolated pro-reform government.
"It is up to the president to approve this decision," Abtahi told the student news agency ISNA, adding that President Mohammad Khatami - who has a total of eight vice presidents in his cabinet - should reach a decision soon.
News of Abtahi's intention to quit came a day after the now conservative-controlled parliament impeached the reformist transport minister, Ahmad Khorram, for mismanagement, corruption, a spate of accidents and favouring foreign firms in handing out government contracts.
Abtahi, a jovial and rotund mid-ranking cleric who is vice president for judicial and parliamentary affairs, has been one of the most outspoken members of Khatami's government.
But he said that working with hard-liners, who took control of parliament in May after most reformists were barred from contesting February elections, had become impossible.
"For some time I have reached the conclusion that given the differences between my political viewpoints and those of the parliament, I cannot fulfil my responsibilities," Abtahi told ISNA.
"For this reason, I have since some time presented my resignation to President Mohammad Khatami so that the understanding between the government and the parliament can be improved," he said.
The vice president could not be immediately reached for further comment. Government spokesman Abodallah Ramazanzadeh confirmed Abtahi had already discussed the issue with Khatami, but added that he did not know if the president - currently on a tour of Algeria, Sudan and Oman - had accepted the resignation.
He also hinted that the government intended to stay in office until Khatami's second and final term ends after the next presidential elections in June 2005.
"We have offered the Iranian nation our plans and we will remain standing to implement these plans. If we are prevented from doing so, that is a different matter, but we will not step aside," he told reporters.
Resignations or threats of resignation have been common in the government since the controversial run-up to February's polls, although so far Khatami has refused to let any of his ministers go.
Abtahi, who is in his mid-40s, held the post of cabinet secretary during Khatami's first term from 1997 to 2001, before being made a vice president.
The cleric is also well known for his frank internet weblog and photo diary, which can be found at www.webnevesht.com, and goes some way towards shattering the widely held view overseas that the regime's ruling clerics are rather staid individuals.
One entry on his website recounts how, during a posting in Lebanon as representative of Iranian media in 1994, he "learned the art of reciprocity, mercifulness and coexistence between Christians and Muslims."
Abtahi is also a government figure who has in the past stuck his neck out, much to the ire of powerful hard-liners who pull most of the strings here.
He was the first official to disclose that Canadian-Iranian photographer Zahra Kazemi was murdered in custody following her arrest in June 2003.
Kazemi's killing badly damaged relations between Canada and Iran, and the hard-line judiciary has been accused of covering up for one of its own officials.