The exiled Crown Prince of Iran has declared that Supreme Leader Ali Khamenei's Islamic Republic 'is collapsing' and has urged citizens and soldiers alike to rise up against the regime.

Reza Pahlavi, the son of the last Shah to rule before Iran's 1979 Islamic Revolution, has long been a prominent critic of Khamenei and says he wants to replace Iran's clerical rule with a 'national and democratic government'.

Now, following days of punishing attacks from Israel that wiped out the upper echelon of Iran's military command, targeted its nuclear facilities and sent Khamenei into hiding, Pahlavi took to social media to issue a rallying cry.

'Khamenei, like a frightened rat, has gone into hiding underground and lost control of the situation,' he declared. 'The regime's apparatus of repression is falling apart.

'All it takes now is a nationwide uprising to put an end to this nightmare once and for all. Now is the time to rise - the time to reclaim Iran.'