YEREVAN, Armenia (AP) — Armenians are set to cast ballots in parliamentary elections, the first vote since the ex-Soviet nation modified its constitution to expand powers of parliament and prime minister.

Polls show the party of President Serzh Sargsyan in the lead. Critics have seen the amendments as part of efforts to keep him in control of the country after he steps down in 2018 due to term limits.

Sargsyan, who has led Armenia since 2008, has rejected the allegations, describing the constitutional changes approved in a 2015 referendum as a step toward strengthening democracy.

The constitutional changes, set to take force after Sargsyan's term ends, envisage largely symbolic powers for the nation's president who will be elected by parliament instead of popular vote like in the past.