Banished from Iran's political mainstream after disputing the results of the 2009 presidential election, reformists are seizing on economic crisis and the threat of war as opportunities to mount a fresh bid for power.
But in gearing up to do so, they face immense challenges, including hardline conservative rivals who accuse them of stoking civil unrest. Many faithful are chastened by relentless repression and the last period of reform-minded government, widely seen as having failed to deliver on its promises.
In the past few weeks, reformist politicians have made statements in Iranian media suggesting they will field a presidential candidate in 2013 - marking an important departure for the movement.
They boycotted parliamentary elections this year, leaving the legislature to be dominated by conservative hardliners backing President Mahmoud Ahmadinejad and the Islamic Republic's ultimate authority, Supreme Leader Ayatollah Ali Khamenei.
"For how much longer should the reformists take a back seat?" asked Mohammad Reza Khatami, a former deputy parliament speaker and brother of reformist ex-president Mohammad Khatami, in an interview with the newspaper Entekhab this month.
He cited his brother's landslide election victories in 1997 and 2001, which he said had eased tensions with world powers as Mohammad Khatami was seen as open to relations with the West.
A reformist triumph in 2013, Mohammad Reza Khatami said, could offer a way out of the current diplomatic stand-off with the powers over Tehran's disputed nuclear program.
Though they remain faithful to Iran's theocratic system, the reformists generally advocate improved relations with the West, more freedom of expression and a loosening of strict Islamic rules governing dress and mingling between the sexes.
They hope to mine popular discontent over Iran's floundering economy, under enormous pressure from international sanctions imposed over its nuclear program, which the West suspects is aimed at developing a bomb while Tehran insists it is peaceful.
The Iranian rial has lost more than 40 percent of its value against the U.S. dollar this year, while oil exports - the government's chief source of income but now embargoed by the European Union - have contracted and inflation, already high, has skyrocketed.
Those troubles should be the reformists' policy focus, rather than political or press freedoms, as they resonate more with the masses, former interior minister Abdollah Nouri told student activists this summer, according to opposition media.
"With the failures of (Ahmadinejad's two terms), people will welcome the reformists," Esmail Gerami-Moghaddam, spokesman for the reformist National Trust Party, told Reuters. "If we enter the elections with a strong candidate, the government will be forced to respect people's votes."
But to participate in politics in any meaningful way, Iran's reformists will have to gain the assent of the unelected Khamenei, who is suspicious of them for their role in the post-election crisis that gripped Iran for months in 2009 and 2010.
Ahmadinejad was declared the winner over reformist Mirhossein Mousavi, sparking allegations of fraud and massive "Green Movement" street protests by Mousavi's supporters.
Dozens of activists were detained, and Mousavi, his wife and his ally Mehdi Karroubi have been under house arrest without trial since February 2011. Conservative hardliners have continued to dominate Iranian politics during that period.
"Those who had the main roles in the sedition should repent for their mistakes and their betrayal. But this won't guarantee their qualification" to run in the elections, read a recent editorial in Kayhan, a hardline newspaper edited by a close confidant of Khamenei and believed to reflect his views.
The clerical paramount leader is unlikely to give his green light to any meaningful reformist participation in politics, according to Meir Javedanfar, an Iran expert at the Interdisciplinary Center in Herzliya, Israel.
An outspoken press flourished briefly and reformists elected a solid majority in parliament during Khatami's presidency from 1997 to 2005, but many of his boldest initiatives were stifled by Khamenei, the conservative judiciary and security services.
In 2005, Ahmadinejad, then the mayor of Tehran, won a first term as president with an estimated 61 percent of the vote, bringing an end to Iran's experimentation with reform.
"Khamenei himself has always been anti-reformist; this is why he created so many problems for Khatami when he was in power," Javedanfar said. "Khamenei knows that giving the reformists a meaningful political platform is likely to create even more infighting within his regime, which is the last thing he wants or needs right now."
Others, however, speculate that Khamenei may allow some reformist stake if he thinks this might reduce the threat of an attack on Iranian nuclear sites by Israel or the United States - although he would probably not cede control over sensitive policy areas such as the nuclear program and foreign policy.
Conservatives have made clear that any reformist candidate in the next presidential vote would have to publicly distance himself from Mousavi and Karroubi. All election candidates must be vetted by the 12-member Guardian Council, giving hardliners an easy way to shut reformists out of politics if they choose.
Hamidreza Moghaddam-Far, an official in Iran's elite Revolutionary Guards, said recently that only those reformists who did not participate in the "sedition" would be allowed to run, according to Mehr News Agency.
MOTIVATING THE BASE
Even if they succeed in convincing conservatives they are no threat to the system, the bigger challenge for the reformists may lie in motivating their political base: youths and women.
Both fervently backed Khatami for his views on promoting better links with the West and relaxing restrictions on personal freedoms, and helped to power Mousavi's campaign in 2009.
But the base now finds itself disillusioned, convinced that Mousavi was the rightful winner of the presidency, and stunned by the harsh measures which the government employed in 2009 and 2010 - including plainclothes militia - to beat back dissent.
"I'm a wide-awake Iranian, and I will never vote in any election in the Islamic Republic again, even if the reformists unite and participate, Khatami is a candidate, and Mousavi and Karroubi are freed," wrote one Iranian blogger who goes by the name Zeytoon. "I remember the last time I voted, and just like many others my vote was plundered."
Several self-described opposition members in the capital Tehran said they had lost faith in the system after 2009 and would not vote for reformists again.
"You shouldn't make the same mistake twice," said one 26-year-old leftist who works as a journalist in Tehran. He was imprisoned for participating in the 2009 protests.
Yasser Azizi, 29, a political and social activist in Tehran, said he voted for the reformists in 2009 but there was "no way" he would vote for their candidate the next time around.
"Any presence of reformists will be an appeasement and compromise with those in power," he said.
A recent article on Kalame, an opposition news website with ties to Mousavi, criticized reformists for relying too much on Iran's formal political system rather than working with informal social movements to push for change.
"This group of reformists considers their whole identity to be tied up with being in power," the article said.
Others disagree. Gerami-Moghaddam conceded that winning the presidency alone would mean little in Iran's system, where power is split between elected and unelected bodies, but said reformists faced little choice but to participate in the system.
"It's true that even if we get the presidency we will not be able to do much," he said.
"But then we can take the next steps in the direction of parliament and government reforms. If we reformists don't participate in the elections, by our own hand we will have handed things over to our rivals."
(Editing by Andrew Torchia and Mark Heinrich)