Iran’s hard-line former President Mahmoud Ahmadinejad registered Sunday as a possible candidate for the presidential election, seeking to regain the country’s top political position after a helicopter crash killed the nation’s president. The populist former leader’s registration puts pressure on Supreme Leader Ayatollah Ali Khamenei. In office, Ahmadinejad openly challenged the 85-year-old cleric, and his attempt to run in 2021 was barred by authorities.

The firebrand, Holocaust-questioning politician’s return comes at a time of heightened tensions between Iran and the West over Tehran’s rapidly advancing nuclear program, its arming of Russia in its war on Ukraine and its wide-reaching crackdowns on dissent. Meanwhile, Iran’s support of militia proxy forces throughout the wider Mideast have been in increased focus as Yemen’s Houthi rebels attack ships in the Red Sea over the Israel-Hamas war in the Gaza Strip.