Pashinyan, a former newspaper editor, came to power in 2018, leading peaceful protests against the corrupt elites who ruled after the collapse of the Soviet Union.
But many Armenians are now disappointed by his inability to implement reforms and his handling of the six-week conflict with Azerbaijan that claimed around 6,000 lives last year.
Pashinyan, 46, has defied calls to resign since the war for control of the breakaway Nagorno-Karabakh region ended in November by signing an unpopular deal that ceded swathes of Armenian land to Azerbaijan.
He has pinned his hopes on the vote to quell the protests and renew his mandate.
But a poisonous campaign has been marred by aggressive rhetoric and fears that the elections will further polarize the country.
In the capital Yerevan, dotted with campaign billboards, Armenians expressed conflicting views about their prime minister.
“This capitulator and traitor must go,” said Gegham Hayrapetyan, 52.
“We need a fresh face, a new politician to address our grievances.”
Sirush Sirunyan, 69, however, blamed Pashinyan’s predecessors for the crisis in the poor South Caucasus country of three million people.
“Nikol is our hero and our savior,” he told AFP.
“The former authorities are responsible for everything. They stole the country for decades.”
Polls show that the Pashinyan Civil Contracted Party is shoulder to shoulder with former President Robert Kocharyan’s electoral bloc.
Both politicians plan to hold multiple demonstrations after the elections.
Pashinyan has stepped up the rhetoric and brandished a hammer at recent campaign rallies in recent weeks, while urging voters to give him a “mandate of steel” to crush critics.
“This is a hammer that belongs to the people, and on June 20 it will fall on their empty heads,” he recently declared, addressing opponents.
He says he expects his party to win 60 percent of the vote, an estimate some pollsters call “fantastic.”
Pashinyan’s enemy and predecessor Serzh Sargsyan, whose bloc is also expected to win seats in parliament, urged his supporters to counter Pashinyan’s hammer with a “club.”
The heated rhetoric of the campaign has prompted warnings from the Armenian ombudsman and raised fears of post-vote unrest if candidates report wrongdoing.
“The probability of street clashes is quite high after elections that were preceded by such an aggressive campaign,” said political analyst Vigen Hakobyan.
A record four electoral blocs and 22 parties are running in the elections and most have campaigned on a pro-Russian platform.
Russia, a long-time ally, helped negotiate a truce agreement with Azerbaijan and its peacekeepers have been deployed in Nagorno-Karabakh.
Only a handful of parties are expected to win seats in parliament.
Pashinyan’s rival Kocharyan, who led Armenia from 1998 to 2008 and counts Russian leader Vladimir Putin among his friends, claims to have run the economy better than current leaders.
“Armenia has been left without a leader,” Kocharyan said at a recent campaign rally.
A poll last week showed that Kocharyan’s bloc led with 24.1 percent, followed by Pashinyan’s party with 23.8 percent and Sargsyan’s bloc with 7.4 percent.
Aram Navasardyan, who heads the pollster that conducted the survey, Marketing Professional Group (MPG), predicted that no one would get more than 30 percent of the vote.
“Emotions are at a fever pitch,” Navasardyan told AFP, adding that the gap between Kocharyan and Pashinyan could widen further.
Around 2.6 million people have the right to vote in 2,008 electoral districts, to elect for a period of five years the minimum number of 101 parliamentarians under a proportional electoral system.
A party needs to win at least 54 percent of the seats in the legislature to form a government, and analysts are not ruling out a second round of polls.
The election will be monitored by observers from the Organization for Security and Cooperation in Europe (OSCE).