Final preparations are underway in Malaysia before voters head to the polls Wednesday in what could be the closest election in its six decades of independence. The contest pits Prime Minister Najib Razak, against his former political mentor, Mahathir Mohamad, who led the country for 22 years until 2003. The official campaign period will end by midnight on Tuesday. Both candidates are scheduled to give speeches this evening.

Malaysians head to the polls Wednesday in what could be the closest election in the country's six decades of independence. Throughout that time, the main political party UM-NO has ruled, in alliance with others. But now leader Najib Razak and his Barisan Nasional alliance face a formidable opponent – the former UMNO prime minister of 22 years, Mahathir Mohamad. As Rian Maelzer reports from Kuala Lumpur, the big question is whether Mahathir can draw enough support from the majority ethnic Malays to lead the opposition to victory.

He may be 92, but Mahathir Mohamad still has considerable pulling power and stamina. Over the past 10 days, he's hurtled around the country to plead with Malaysians to help oust the alliance he led for 22 years.

The issues he's been hammering away at -- like the unpopular goods and services tax, and the alleged misuse of billions of dollars by the state investment firm 1MBD -- strike a chord with many younger voters.

ADRIAN CHANG EVENTS PLANNER "The thing that I would like addressed if a new government in power, the gst, rising cost of living and the numerous corruption scandals that has hit us."

The opposition Pakatan Harapan can expect to do well in urban areas and are again likely sweep up the votes of non-Malays, especially ethnic Chinese.

KEITH LEONG POLITICAL ANALYST, KRA GROUP "The Malay electorate which is the majority, which is crucial, have been reluctant to vote for the opposition. So it could be argued that Mahathir's place, Mahathir's presence in the opposition would finally allow them to tap into these voters."

Prime Minister Najib Razak argues that the Barisan Nasional will best look out for the interests of ethnic-Malays by preserving affirmative action policies and protecting Islam. The BN promises larger cash handouts for the lower income groups and a rise in the minimum wage.

The opposition's manifesto promises to scrap the goods and services tax, and unpopular road tolls, as well as to tackle corruption and abuse of power.

But the manifestos can do more than just lay out lofty promises.

KEITH LEONG ANALYST, KRA GROUP "It certainly does energise their respective bases and maybe that is what will be decisive going into the election: which side has a more energized base, who wants it more, who's going to work harder for it."

RIAN MAELZER KUALA LUMPUR "There is one critical factor that makes the outcome particularly unpredictable. The Islamist party PAS that was part of the opposition alliance in the past two elections will now run against them, and BN, leading to many three-cornered fights."

And in the first-past-the-post electoral system, a split in the anti-BN vote could be enough to allow Najib and BN to waltz back into power.