DUBAI The buzzing crowds and human chains of Iran's disputed election in 2009 may be nowhere to be seen ahead of Friday's poll but the activists who fired up the protests then are keeping the flame alive online.
After the sustained demonstrations of 2009, Iran's hardline establishment barred reformist candidates and unauthorized gatherings, and arrested many activists on charges of sedition.
Now, reformists seeking to spread the word about moderate candidates have turned to online platforms like the messaging app Telegram.
"There is no way we are allowed to have that street presence again," said Mohammadreza Jalaeipour, a political activist who spent five months in solitary confinement for running a campaign supporting a reformist candidate in 2009.
Now a researcher at the Center for Middle Eastern Studies at Harvard, Jalaeipour runs a social media and Telegram campaign that includes the Green Online Chain, harking back to the Green Chain of 2009 when activists in green headbands held hands to form a 20-km (12-mile) line down Tehran's Valiasr Street.
Although activists communicated in closed Facebook groups before the 2013 presidential elections, in which the reformist vote helped centrist Hassan Rouhani to a landslide, they could not replicate the reach they had offline in 2009, he said.
Telegram, which has an estimated 20 million users in Iran or a quarter of the population, has "totally changed the scene", Jalaeipour said.
"Former President Khatami's video message in support of the coalition of moderated and reformists has been viewed more than three million times on Telegram in one day. Another poster we shared on Telegram was viewed by a million people only in 12 hours. How we could print and distribute that many posters?" he said.
Jalaeipour, now 33, is convinced that campaigning on social media is not only cheap, but more efficient, though he added that it cannot substitute for face-to-face campaigning.
Iranians have created thousands of groups on Telegram that are constantly forwarding material from one group to another, something that is rare on platforms such as Facebook where people tend to "like" posts rather than "share" them.
Berlin-based Telegram, launched in 2013 by the exiled founder of Russia's most popular social network site Vkontakte, has become popular among activists and ordinary Iranians because it is seen as being more secure than its rivals.
Moreover, unlike Facebook and Twitter, the authorities have not blocked Telegram outright -- though it has agreed to block access to pornographic content in line with what it said was corporate policy.
Ironically, hardliners are also using the new platform. The Basij volunteer militia, which was involved in putting down the 2009 protests, use Telegram to alert its members to street gatherings, a source close to the group said.
The Basij has also created Telegram channels in which administrators urge members to vote for certain candidates in Friday's election, added the source, who subscribes to one of the channels.
Much as reformist voters have rallied around moderate candidates as a way to keep conservatives out, the Basij channels make suggestions about which conservative candidates can be sacrificed to ensure an overall win, the source said.
(Reporting by Bozorgmehr Sharafedin; Writing by Sam Wilkin; Editing by Sonya Hepinstall)