A final deal to resolve the Iranian nuclear dispute could heighten domestic political tensions with two major elections looming in the Islamic Republic, analysts and officials said.

Easing economic sanctions if a deal is reached will bolster President Hassan Rouhani's position within Iran's complex power structure, bringing a political boost for liberal candidates in 2016 elections for parliament and for the Assembly of Experts, a clerical body with nominal power over the supreme leader.

Supreme Leader Ayatollah Ali Khamenei, who has the final say on all matters of state, has backed Rouhani's efforts to pursue a nuclear settlement and his dealings with the United States so as to improve the parlous state of Iran's economy.