Following are key electoral facts, players and issues.
The Barisan Nasional (National Front) ruling coalition has governed Malaysia since independence and is one of the world's longest-serving governments.
But a three-party alliance known today as the Pakatan Rakyat (People's Pact) put in the strongest opposition performance ever in 2008 elections, fuelling speculation it could finally dethrone Barisan in Sunday's polls.
The ruling coalition
- Completely dominated by Malaysia's most powerful party - the United Malays National Organisation (UMNO) - which represents majority Muslim Malays. Includes 12 other junior parties.
- Headed by Prime Minister Najib Razak, 59, son of Malaysia's second prime minister. Najib replaced his predecessor after the 2008 setback and has yet to secure his own mandate.
Strengths: Strong record of economic growth over the years; has largely escaped damage from the global downturn; has generally prevented racial unrest in the multi-ethnic nation; promises stability and further economic growth.
Weaknesses: Plagued by corruption scandals and accusations of authoritarianism, rights abuses and racial fear-mongering; Najib is seen as struggling to convince powerful UMNO conservatives of the need for change.
- Comprises the multi-ethnic People's Justice Party, the Pan-Malaysian Islamic Party (PAS) representing Muslim Malays, and the Democratic Action Party (DAP) dominated by ethnic Chinese.
- Presumed prime ministerial candidate is Anwar Ibrahim, Barisan's heir-apparent until his stunning 1998 ouster and his widely criticised jailing for corruption and sodomy amid a power struggle.
Strengths: Momentum and a creditable governance record in four states won in 2008; taps into anger among minorities over Barisan's preferential policies for Malays; promises populist policies and an end to authoritarianism.
Weaknesses: Frequently plagued by infighting, especially between PAS and DAP; at a clear disadvantage in funding; electoral system skewed in the government's favour; has no access to government-controlled mainstream media.
Facts and figures
- Malaysia's 13th general election since independence.
- Voters choose 222 representatives for the lower house of parliament in a first-past-the-post system; a government can be formed with at least 112 seats. Voters also select 505 representatives for 12 state assemblies.
- Current allocations: Barisan Nasional 135; Pakatan Rakyat 75; Independent 12.
- 13.3 million of Malaysia's 28 million people are registered to vote, an increase of 2.4 million from the 2008 election.
Key public issues
Corruption: Estimated to cost the country billions of dollars a year. Recurring high-profile graft scandals linked to the government cause anger.
Inflation: Costs of basic goods such as fuel and food have risen steadily.
Ethnic relations: Ethnic Chinese and Indians increasingly chafe under decades-old policies that accord advantages to majority Malays in business, education and other spheres, and fear a perceived "Islamisation".
Crime: Fears over crime and personal safety are on the rise.
Electoral system: Critics say it blatantly favours the government and warn of fraud risks including an electoral roll believed to be rife with irregularities.