In his more than three decades in charge of the Islamic Republic of Iran, Ayatollah Ali Khamenei has battled to consolidate power at home and expand the regime’s influence across the region. But the So-year-old leader is facing his toughest challenge yet as he seeks to unify a fractured establishment and calm people angry at the alleged cover-up of the cause of a plane crash last week.

In recent days, public mourning at the US assassination of military commander Qassem Soleimani has turned to rage after it emerged that Iran had mistakenly shot down a Ukraine International Airlines jet, killing 176 people. “The relationship between the nation and the state has never been as split as it is today, while even inside the political system, politicians accuse each other of hiding and pretending,” said one reformist analyst.

There are now “accusations that the state is systematically lying and hence Ayatollah Khamenei has become the main target of public wrath [as the top leader] and the government of [Hassan] Rouhani is seen as too lame to make any changes”. Under Iran’s theocratic rule, the supreme leader is seen as infallible, enjoying “absolute” authority over all the country’s affairs including the military. After the death of Soleimani, he authorized the Islamic Revolutionary Guard Corps to launch missile attacks on US forces in Iraq. No American soldiers were killed and Iran sent a message to the US that that would be the only direct military retaliation if the US did not itself retaliate.

The supreme leader won plaudits at home for a strategy that saw him avenge Soleimani’s death, but avoid war with the US. “Which regional leader, or any leader in the world, would ever dare to challenge the US the way Mr Khamenei did?” said one regime insider. “Nobody.”