If Iranian voters deny President Mahmoud Ahmadinejad re-election on Friday, it may be more a verdict on his economic performance than on his fierce rhetoric against the United States and Israel, his defense of Iran's nuclear policy or his persistent questioning of the Holocaust.

Ahmadinejad, 53, grabbed 62 percent of the vote in the 2005 presidential poll, upsetting widespread predictions of victory for the seasoned former President Akbar Hashemi Rafsanjani.

He swept to power with the backing of Iran's devout poor, especially those in rural areas, who felt neglected by past governments and liked his promise to put oil wealth on the table of every family in a nation of over 70 million people.

Ahmadinejad has distributed loans, money and other help for local needs on his frequent provincial tours, but critics say his free-spending policies have fueled inflation and squandered windfall petrodollars without reducing unemployment.

Since he took power, prices of food, fuel and other basics have soared, hitting more than 15 million Iranian families who live on less than $600 a month, according to official figures.

Ahmadinejad, who blames inflation on a global surge in food and fuel prices that peaked last year, has pursued unorthodox economic policies such as trying to curb prices while setting interest rates well below inflation, now less than 18 percent.

Born a blacksmith's son in the farming village of Aradan, 100 km (62 miles) southeast of Tehran, his family moved to the capital in his early childhood. He studied engineering and has alternated between teaching and administrative posts.

Ahmadinejad, a small man who wears open-necked shirts and windbreakers, plays on his modest origins and lifestyle. After the 1979 revolution, he joined the elite Revolutionary Guard.

His rise to power appeared to signal a return to the stern revolutionary roots of the Islamic Republic's founder, Ayatollah Ruhollah Khomeini, after hardliners snuffed out the reformist challenge when Mohammad Khatami was president from 1997 to 2005.

Ahmadinejad often denounces Western hegemony as well as the U.N. and U.S. sanctions that have raised trade costs and deterred Western investment in Iran's oil and gas sector.

During his term, the U.N. Security Council has imposed three sets of sanctions on Iran over its nuclear program, which the West suspects has military aims, not merely civilian ones as Tehran insists. Ahmadinejad's moderate rivals say his fiery anti-Western talk has helped isolate Iran diplomatically.

The incumbent is basking in support from Iran's Supreme Leader, Ayatollah Ali Khamenei, who has called on Iranians to vote for an anti-Western candidate. However, this apparent endorsement could provoke a backlash from voters who stayed at home in 2005 but might relish a chance to say 'no' to Khamenei.

The supreme leader ultimately calls the shots in Iran, where the president can only influence policy, not decide it.

It would be rash to assume that Iran's nuclear policy or its decision on how to respond to diplomatic overtures by U.S. President Barack Obama will change, even if a moderate candidate defeats Ahmadinejad in June, analysts say.

His challengers are Mirhossein Mousavi, prime minister during the 1980-88 war with Iraq, former parliament speaker Mehdi Karoubi and former Revolutionary Guard commander Mohsen Rezaie. All three advocate a less abrasive foreign policy.

Presidents can run for two consecutive four-year terms before they must step down. They can run again at a later date.

(Editing by Alistair Lyon)