Iran has also faced severe sanctions by the United Nations, over its alleged nuclear programme, while inflation has climbed steadily at over 27 per cent.

However, Ahmadinejad's hardline policies have gained the support of Iran's Supreme Leader Ayatollah Ali Khamenei, who has endorsed the President's stance on the country's nuclear programme.

In spite of immense popular support for  Mousavi, experts predict an easy win for Ahmadinejad, who enjoys Khamenei's support.

According to the Iranian constitution, Supreme Leader Khamenei, not the President, is Iran's highest-ranking official.