Updated

Voters in the oil-rich Caspian Sea nation of Azerbaijan are set to cast their ballots in a snap presidential election Wednesday that is all but certain to extend the rule of the country's long-serving leader.

President Ilham Aliyev is expected to win the vote by a landslide. Leading opposition parties boycotted the race, leaving seven token challengers. Opinion surveys have put support for Aliyev at over 80 percent.

The 56-year old leader has governed Azerbaijan since 2003, when he succeeded his father, Geidar Aliyev, who ruled Azerbaijan for the greater part of three decades.

Since Aliyev won the last election in 2013, Azerbaijan's Constitution has been amended extend the presidential term from five to seven years. Aliyev's critics denounced the 2016 plebiscite as effectively cementing a dynastic rule.