As mass protests by supporters of reformist Presidential candidate Mir Hussein Mousavi continue, Iran’s Supreme Leader, Ayatollah Ali Khamenei, will address the nation later today.Khamenei has already urged Iranians to support hardline President Mahmoud Ahmadinejad – but Mousavi’s supporters have ignored the call. The tone and content Khamenei’s speech at Friday Prayers could now be pivotal in Iran’s on going political crisis. Those inside and outside Iran will be watching to see whether he favours Ahmadinejad or Mousavi. Backing either carries risks. If he supports Mousavi he will undermine conservative hardliners. If he backs Ahmadinejad, who has defended the legitimacy of the vote, he could spark more mass protests from Mousavi supporters. It is a delicate balancing act upon which so much depends. Iranian state media has reported seven or eight people have been killed in protests since the election result was published on June 13th. And the intensity of the violence can been seen in latest pictures from Teheran University – a campus which has seen much bloodshed since the Iranian Revolution in 1979.