Iran is bracing for a fresh showdown between supporters of President Mahmoud Ahmadinejad and some conservatives as simmering tensions build in the run-up to the March 2012 Parliamentary election.

The aborted resignation of intelligence minister Heydar Moslehi set off a conservative storm against the president's entourage, with the focus on his chief of staff and key adviser Esfandiar Rahim Mashaie.

On April 17, Iranian media announced Moslehi, close to all-powerful supreme leader Ayatollah Ali Khamenei, had been dismissed after he tried to sack one of his deputies, who reportedly has close ties to Mashaie.

But minutes later, Ayatollah Khamenei, who holds the ultimate authority in the country, personally intervened to overturn the dismissal.

Under the constitution, the president is in charge of appointing ministers — who then need to be approved by the Parliament — as well as dismissing them.

But an unwritten law requires top ministers, including the intelligence, defence, interior and foreign affairs, to have the tacit approval of the supreme leader.

Khamenei's intervention also provided a supreme opportunity for the conservatives to mount fresh attacks against Ahmadinejad, with their media accusing Mashaie of orchestrating the "current deviation".

Mashaie, a close relative of Ahmadinejad, and who is rumoured to be the President's choice to succeed him in 2013, has for years been the bane of the religious traditionalists in the Iranian regime.

In July 2009, Khamenei ordered the hardline Ahmadinejad to reverse the appointment of Mashaie as his first vice-president following a bitter outcry from the conservative camp.

Mashaie was then strongly condemned for holding nationalistic views pertaining to the pre-Islamic Iran, and for remarks attributed to him despite his denial that Iran was "friend of the Israeli people" — a deep-seated taboo considering that Tehran does not recognise Israel.

And these days, he is also criticised for his efforts to push for an "Iranian school of Islam" and his liberalism on cultural and social issues.

"The diversionary trend is hiding behind a popular, accepted and justifiable figure," Brigadier General Mohammad Ali Jafari, commander of the powerful Revolutionary Guards, said on Sunday in an allusion to Mashaie.

"This movement will definitely act against the (Islamic) revolution in the future," Jafari warned.

Mashaie, who has worked closely with Ahmadinejad for over 25 years, has not even been spared from the wrath of the President's mentor, ultra-conservative cleric Ayatollah Mesbah Yazdi who has accused him of seeking to create a "Masonic organisation" and "to deal a blow to Islam on a daily basis."

On Saturday, a top presidential adviser, Ali Akbar Javanfekr who also heads the official IRNA news agency, responded to the mounting criticism, saying the attacks "could intentionally or unintentionally put the plan into action to overthrow" the Ahmadinejad presidency.

The crisis forced Khamenei on Saturday to calm the brewing storm, issuing a warning to officials against rising gaps among the ranking echelons which he said were benefiting "the enemy."

He explained that as the supreme leader he only intervenes in the country's politics if the Islamic republic's interests are being "neglected," but pledged his ostensible support for Ahmadinejad and his government who in his words "are working day and night to serve the country."

But what the new wrangling portends to be is the flexing of power against the backdrop of a looming battle for the Parliamentary election in 2012, as well as the one that would appoint the successor of Ahmadinejad the in 2012.

With the absence of the reformists in the next vote, who have been marginalised after disputing the re-election of Ahmadinejad in 2009, analysts believe the battle for power has already started among the conservatives.

"The President and his comrades, including Mr Mashaie, have a laid-out plan to contest the future election," said Hojatoleslam Abbas Amiri-Far, head of the cultural council of the presidency.

"And they will definitely beat the conservatives in the competition," he said, while predicting "more divisions" among the ranks in the coming months.