Malaysians vote on Sunday in an election that could weaken or even end the rule of one of the world's longest-lived coalitions, which faces a stiff challenge from an opposition pledging to clean up politics and end race-based policies.
Led by former finance minister Anwar Ibrahim, the opposition is aiming to build on startling electoral gains in 2008, when the Barisan Nasional (BN), or National Front, ruling coalition lost its customary two-thirds parliamentary majority.
The historic result signalled a breakdown in traditional politics as minority ethnic Chinese and ethnic Indians, as well as many majority Malays, rejected the National Front's brand of race-based patronage that has ensured stability in the Southeast Asian nation but led to corruption and widening inequality.
Under Prime Minister Najib Razak, the blue-blood son of a former leader, the coalition has tried to win over a growing middle class with social reforms and secure traditional voters with a $2.6 billion deluge of cash handouts to poor families.
He can point to robust growth of 5.6 percent last year as evidence that his Economic Transformation Program to double incomes by 2020 is bearing fruit, while warning that the untested three-party opposition would spark economic ruin.
Najib, who is personally more popular than his party, has had some success in steadying the ship since he was installed as head of the dominant United Malays National Organisation (UMNO) in 2009. Formidable advantages such as the coalition's control of mainstream media, its deep pockets and a skewed electoral system make it the clear favourite.
But opinion polls suggest a tightening race that could further reduce the coalition's majority and lead the opposition to dispute the result over claims of election fraud.
The opposition alliance has been buoyed by unusually large, enthusiastic turnouts at campaign rallies in recent days. It says its "X factor" may be a surge in young, first-time voters who are more likely to be attracted to its call for change after 56 years of rule by the BN coalition.
"The momentum is far greater in 2013," Nurul Izzah, Anwar's daughter and an opposition member of parliament, said at a meeting with journalists and foreign diplomats on Friday.
"I've never enjoyed so much support everywhere. That's our only hope, to ensure a good turnout."
A failure to improve on 2008's performance, when the BN won 140 seats in the 222-seat parliament, could threaten Najib's position and his reform programme. Conservative forces in UMNO, unhappy with his tentative efforts to roll back affirmative action policies favouring ethnic Malays, are waiting in the wings to challenge his leadership.
ANWAR'S LAST STAND?
The election represents possibly the last chance to lead Malaysia for Anwar, a former rising UMNO star who was sacked and jailed for six years in 1998 following a feud with then prime minister Mahathir Mohamad, who remains an influential figure.
The 65-year-old former deputy prime minister says his corruption and sodomy conviction was trumped up. He received a new lease on political life last year when a court acquitted him of a second sodomy charge.
His alliance, which includes an awkward partnership between a secular ethnic Chinese party with an Islamist party, is riding a growing trend of civil-society activism, which has been most evident in a series of big street protests in recent years calling for reform of the electoral system.
A clumsy police response to a rally in 2011 led Najib to roll back draconian colonial-era security laws, though critics say he did not go far enough and demands for electoral reform have not been fully addressed.
A narrow victory for the ruling coalition on Sunday would almost certainly spark opposition complaints of voter fraud, which could spill over in street protests. Anwar has accused the coalition of flying up to 40,000 "dubious" voters across the country to vote in close races.
The opposition, which can present a viable alternative from its record of governing in four states it took over in 2008, is running on a platform of transparency and integrity, saying it will break down an entrenched network of patronage that has grown up between UMNO and favoured business tycoons.
It pledges to replace policies favouring ethnic Malays in housing, business and education with needs-based assistance.
It can bank on ethnic Chinese voters, who make up about 25 percent of Malaysians and who abandoned the ruling BN coalition in 2008. Maintaining its momentum among ethnic Malay voters may be more difficult amid warnings from the BN that they would be at risk from Chinese economic domination if the opposition won.
"We've seen a consolidation of Chinese support. I think the question for us to a large extent is how the silent majority of Malay voters will go," said Ong Kian Ming, who is running for a seat in an ethnically diverse constituency near Kuala Lumpur.