By Tim Butcher, Middle East Correspondent
In an eight-strong field that includes hard-liners and reformers, civilians and former officers, Mr Rafsanjani, a two-term president whose career stretches back three decades, is expected to prevail.
After a lacklustre campaign, which flickered to life only during a row over the number of reformists allowed to stand, Iran’s 40 million registered voters are due to cast their ballots on Friday.
But the failure of the outgoing reformist president, Mohammed Khatami, to create jobs, dismantle inefficient state industries and reduce the power of Iran’s conservative clerics, has greatly reduced public interest.
A low turnout is expected and, for the first time since the 1979 revolution recreated Iran as an Islamic republic, a second round of voting is likely to be needed for a presidential election.
This domestic apathy runs counter to the interest being paid by America and Europe to the result, which could have an important bearing on the continuing row about Iran’s nuclear plans.
Washington and the West will hope that the new president is willing to accept promises of economic benefits in exchange for the scrapping of any possible nuclear weapons programme.
Although reliable polling is not carried out in Iran, Mr Rafsanjani, who was the middleman in the notorious Iran-Contra scandal when Washington secretly supplied Teheran with weapons, is unlikely to receive the more than 50 per cent of votes required to win outright, so a second round is expected later this month.
Mr Rafsanjani, regarded as a pragmatist with strong connections to Iran’s clerical elite, has raised the possibility of improved relations with the United States.
Diplomatic relations were broken off with America during the 1980 embassy siege crisis in Teheran and Iran was included in President George W Bush’s “axis of evil”.
“There is no doubt that America is a superpower of the world and we cannot ignore them,” Mr Rafsanjani said in comments widely interpreted as an olive branch towards Washington.
But he then indicated he would take a hard-line position on the nuclear question, saying it was Iran’s basic legal right to explore the option of nuclear power and he would never give it up. “It is like giving away part of our territory,” he said.
The campaign was marred on Sunday by a string of bomb attacks, a rarity in the tightly controlled country, in which nine people died and 75 were injured.
But the campaign has been more remarkable for the expanded use of modern electioneering techniques, including the use of focus groups by Mohammed Bagher Qalibaf, the leading conservative challenger and a former national police chief.
Members of his campaign team said they took Tony Blair’s New Labour election machine as a model, saying that, while they did not agree with Mr Blair’s policies, his methods of targeting particular voters and issues were important. They have also organised large rallies and walkabouts.
Pop music, direct e-mailing and political broadcasts by CD have been employed in the election but it has failed to ignite the public interest shown during the campaign that brought Mr Khatami to power in 1997.
But while Mr Khatami promised to deal with this systemic inertia, he failed to outmanoeuvre the clerical bloc. Two reformist candidates were allowed to stand in this week’s election, after Iran’s spiritual leader, Ayatollah Ali Khamenei, publicly rebuked the election selection committee from banning them.
Five more conservative candidates are standing. They include the mayor of Teheran, who struck a populist note by promising to cut the hands off corrupt officials.
Another of the conservative candidates stood on a ticket of promising cash to every Iranian voter, a monthly stipend of about £40.
