POLLS have opened in an early presidential election in the former Soviet republic of Azerbaijan.

Voting began on Wednesday in the oil-rich Caspian Sea nation where incumbent Ilham Aliyev is expected to win by a landslide.

Around 80 per cent of voters are thought to support the president, who succeeded his father in 2003.

Heydar Aliyev ruled Azerbaijan initially as Communist Party leader before becoming the post-Soviet president for almost three decades.

Since his son won the last election in 2013, Azerbaijan’s constitution has been amended to extend the presidential term from five to seven years.

Aliyev’s critics denounced the 2016 plebiscite as effectively cementing a dynastic rule.

The election was originally scheduled to be take place in the autumn but was brought forward to April.

Officials said the move was made because the country would be busy with various high-profile events in late 2018.

Although the leader of the majority Shia Muslim nation has faced criticism for for alleged human rights abuses and suppression of dissent, he has sought to ally Azerbaijan to the West – offsetting Russian influence in the Caspian region.