Former Iranian president Mahmoud Ahmadinejad has filed a nomination to run in the upcoming elections, marking a turnaround from his earlier promise not to contest.

“The leader advised me not to participate in the elections, and I accepted. His advice, however, shouldn’t be taken to mean that I’m banned,” he told reporters after submitting his candidature.

The Islamic Republic’s Supreme Leader Ayatollah Ali Khamenei had in September 2016 advised Ahmadinejad, who held office from 2005 to 2013, not to contest in the 19 May elections.

Ahmadinejad became infamous during his presidency for his widely criticised comments calling for the destruction of Israel and for his denial of the Jewish Holocaust. It was during his tenure that nuclear-related sanctions were imposed on Iran, effectively cutting off the economy from engaging with the rest of the world.

He was also widely resented at home, particularly by Iranian youth for strengthening hardliners and instituting religious scholars to head universities.

Current Iranian President Hasan Rouhani with his moderate stance towards engagement with western countries and opening up the country’s economy, had been the longstanding favourite to win the elections. However the appointment of US President Donald Trump, who opposed the Joint Comprehensive Plan of Action in his election campaign, has cast doubts on Rouhani’s re-election as hardliners seek to adopt a more confrontational approach to the US.

Hardline cleric Ebrahim Raisi also put his name forward in the race last week saying it was his “religious and revolutionary responsibility” to run for president. Four other candidates have been nominated by Iran’s hardliners to contest next month. The death of Iran’s reform-minded revolutionary cleric-turned-president Ali Akbar Rafsanjani leaves Rouhani as one of the few voices of moderation within Iranian body politic.

Iran’s Guardian Council vets nominations and could likely block Rouhani’s and Ahmadinejad’s bids later this month.

Ahmadinejad, who kept a low profile after his presidency joined Twitter earlier this year, tweeting video messages in English in an attempt to offer a softer image to the international community as well as voters at home that he had left behind the firebrand rhetoric employed during his presidency.

The outcome of the election will set the pace for Iran’s attempts to develop its economy, particularly its ageing energy infrastructure after years of sanctions.

Foreign oil companies, which were pre-qualified in January 2017 to bid on tendered oil and gas blocks, have yet to be provided with the Iran Petroleum Contract. According to the energy minister the new contract model is still under review. A more hardline outcome will deter investment into Iran and would stall billions of dollars’ worth of projects in the pipeline.