Iran’s former reformist president Mohammad Khatami has called on voters to re-elect President Hassan Rouhani in the May 19 presidential elections.

In a video posted online, he urged voters to cast their ballot for Rouhani to ensure the “implementation of social and economic justice.”

Khatami lauded the accomplishments of Rouhani’s administration, which he described as successful, despite facing “limitations and problems.”

The former premier is considered to have played a key role in Rouhani’s ascension to the presidency in 2013, apparently convincing reformist challenger Mohammad Reza Aref to step aside.

Iranian President Hassan Rouhani, center, waves to his supporters accompanied by Vice President for Women and Family Affairs Shahindokht Molaverdi, left, at a campaign rally for the May 19 presidential election, in Tehran, Iran, May 9, 2017. (AP/Vahid Salemi)

Iranian President Hassan Rouhani, center, waves to his supporters accompanied by Vice President for Women and Family Affairs Shahindokht Molaverdi, left, at a campaign rally for the May 19 presidential election, in Tehran, Iran, May 9, 2017. (AP/Vahid Salemi)

Khatami, who served as president from 1997 to 2005, is considered to be the spiritual leader of Iran’s reformists, and remains influential among youth, despite being under a media ban.

The May 19 vote is seen largely as a referendum on Rouhani’s outreach to the rest of the world following the country’s landmark 2015 nuclear accord with world powers.

Though he is leading in official polls, Rouhani faces a tough fight for re-election against conservative rivals who accuse him of failing to boost the struggling economy.

Rouhani faces five opponents in the election, but some may well drop out in the coming days to boost the chances of the most-prominent candidates. Eshaq Jahangiri, one of Rouhani’s vice presidents, is expected to leave the race to help his boss.