Malaysia is set to hold a general election on May 9, the Elections Commission said, in what could be the toughest test of the ruling coalition’s 61-year grip on power.

Embattled Prime Minister Najib Razak is under pressure to deliver an emphatic win for the Barisan Nasional (BN) coalition, as he struggles to appease Malaysians unhappy with rising costs and a multi-billion dollar scandal at a state fund he founded.

The 64-year-old is expected to retain power due to the BN’s firm grip on Malaysia’s weakened institutions, and what critics claim are efforts by the government to rig the election through gerrymandering and other forms of cheating.

But he faces a tough challenge from his old mentor and the country’s most seasoned campaigner, former Prime Minister Mahathir Mohamad.

Announcing the poll date, which falls on a weekday, the Election Commission on Tuesday set an 11-day campaign period, shorter than the 15 days allotted for the 2013 polls.

It said 14.94 million people are eligible to vote, including 1.7 million new voters.

The combination of the election being held on a Wednesday – the first time in almost 20 years that a Malaysian election has been set for a weekday – and the shorter campaign has fueled concerns over low voter turnout.

“Not only is the campaign period only the minimum 11 days, but polling day is on a Wednesday, a working day and a school day,” said Bersih, an electoral reform group.

“We can now expect to see even lower voter turnout and further hardship for all voters,” the group said.

‘Unfair’ elections

The opposition has said previously that it expects the election to be unfair after parliament approved plans to redraw electoral boundaries and pushed through an anti-fake news bill, changes critics say will favour Najib.

The government and the Election Commission have rejected these accusations. The commission said on Tuesday it had appointed 14 international observers and 14 local observers.

Mahathir said his party was confident of a win, despite the unusual weekday polling, which meant that Malaysians abroad might not be able to return home to vote.

“We think we will be able to defeat Barisan Nasional in this election,” he told a news conference.

But analysts said unseating Najib will be tough.

“We have democratic institutions, but we also have practices that border on authoritarianism,” said Ibrahim Suffian, an analyst at the polling firm Merdeka Centre.

“And the ruling party has been in power so long that they’ve mastered the art of managing the competition, and working with the rules,” he told Al Jazeera.

“But having said that, elections are still fairly competitive.”

‘Ultimate survival test for Najib’

A strong victory is pivotal for Najib ahead of year-end party elections in his United Malays National Organization, or UMNO, the linchpin of the coalition that has ruled Malaysia since independence from Britain in 1957.

“I would consider this election the ultimate test of survival for Najib,” said Rashaad Ali, research analyst with the S Rajaratnam School of International Studies in Singapore.

“If Najib fails to deliver a strong result, voices of dissent within UMNO will surely grow louder, making his position as leader untenable. If he does well in the election, it would be the biggest consolidation of his position,” he told The Associated Press.

Najib has overseen a growing economy buoyed by a recovery in global crude oil prices and increased trade and infrastructure investment from Malaysia’s largest trading partner, China.

But he has been plagued by reports of alleged financial mismanagement at state fund 1Malaysia Development Berhad (1MDB), including that $681m was deposited into his personal bank account.

Najib has denied any wrongdoing in connection with 1MDB, but the scandal created a rift with Mahathir, who has become the prime minister’s harshest critic.