Q+A: How likely is it that Iran protests will spread?

TEHRAN (Reuters) - Since Iran's disputed presidential election on June 12, supporters of defeated moderate candidate Mirhossein Mousavi have been taking to the streets, clashing with police.

Here is a summary of events leading up to the protests, and prospects for continued unrest:

HOW UNEXPECTED WAS THE RESULT?

The scale of Ahmadinejad's first round victory -- he won 63 percent of the vote to Mousavi's 34 percent -- surprised many Iranians, who widely predicted Mousavi would win.

A few days ahead of the vote, opinion polls -- although notoriously inaccurate in Iran -- reinforced the view of pundits and diplomats that Mousavi was seeing a surge in support that could win him the election, possibly in a second-round run-off.

Two U.S. non-profit groups said on Monday that their nationwide telephone survey had had Ahmadinejad leading Mousavi by more than two-to-one, although the poll was conducted three weeks before the vote, when Mousavi's campaign had barely begun.

Many Iranian men and women have protested against the result, and the political unrest has been the most serious in Iran since the 1979 Islamic revolution.

In contrast to an uprising at Tehran University 10 years ago, protesters include older Iranians -- not just students. Demonstrations have taken place in central and northern Tehran, and five other cities.

Analysts say many factors could have contributed to Ahmadinejad's victory, from the strong support he enjoys in poor rural areas to vote-rigging.

"Whatever it was, Ahmadinejad's chances would have been less in a runoff because supporters of the other moderate candidates would vote for Mousavi," one analyst said.

WHAT IF THE UNREST SPREADS?

In what appeared to be a first concession by the authorities to the protest movement, Iran's top legislative body on Tuesday said it was ready to recount votes but the 12-man Guardian Council ruled out annulling the disputed poll.

Iranians outraged by Mousavi's defeat in what they viewed as a stolen election plan another rally on Tuesday, even though seven people were killed on Monday on the fringes of a huge march through the streets of Tehran.

The establishment may use force if necessary to defend the poll result, a reminder to Iranians that home-grown definitions of freedom are more restrictive than their Western counterparts.

Many Mousavi backers said they were voting for an end to a climate of social repression and isolation that they say has pervaded Iranian society since Ahmadinejad was elected in 2005.

Analysts say the ongoing unrest is undermining the legitimacy of the Islamic Republic, since it has taken place in defiance of a call by Supreme Leader Ayatollah Ali Khamenei, who urged Iranians to support Ahmadinejad.

"They may use force if necessary to stop it," said the analyst.

Ahmadinejad has said the high turnout of 84 percent underlined the legitimacy of his re-election.

Mousavi has officially appealed against the result. But analysts believe a re-run could only be held with the intervention of Khamenei, who has publicly backed Ahmadinejad.

"Such a decision by Khamenei would reveal how concerned the leadership is about the spread of protests," analyst Mahmoud Shafeghat said.

A TURNING POINT?

Analysts say the protests could be a turning point in years of struggle between Iranian reformists and hardliners.

Although the many protesters are concerned about broad issues such as free speech and social freedoms, their slogans and chants have targeted Ahmadinejad.

Even if he remains in power, his government may face more protests during his second term.

Analysts say Iranians who grew used to weeks of pre-election street rallies, followed by three days of protest, may have lost their fears of public demonstration.

"Even a football match can spark nationwide riots in the next four years because Ahmadinejad's position has been weakened," said the analyst who declined to be named.

He said the protests had underscored shortcomings in the tactics of the Ahmadinejad camp, which appears simply to be trying to outlast its moderate rivals.

THE LIKELIEST SCENARIO?

Analysts say it is very unlikely Khamenei will intervene to call for a re-run because it could lead to moderates winning subsequent elections, including the next parliamentary election in 2012.

The fate of the protests could hinge on whether Mousavi -- who served as prime minister for eight years and was an ally of the late Ayatollah Ruhollah Khomeini -- wants to become an opposition figure.

"He is part of the Islamic Republic and believes in religious leadership," the analyst said. "He would not want to put the system in danger."

Khamenei will lead Friday prayers in Tehran this week. If, as seems likely, he publicly orders an end to the protests, Mousavi may heed the call.

(Editing by Samia Nakhoul and Kevin Liffey)