Anwar, the pending prime minister of Malaysia, will return to Parliament in a by-election

Anwar Ibrahim has set his sights on a return to Malaysia's front-line policy, as the vote began in a partial poll that will likely seal the remarkable political resurrection of the opposition figure, once incarcerated.

Winning the seat is a key requirement for Anwar to succeed Prime Minister Mahathir Mohamad, aged 93, who imprisoned his former protege and heir on charges of sodomy and corruption in 1998, when their relationship broke down.

Malaysian Prime Minister Mahathir Mohamad (R) shows his support for Anwar Ibrahim during the campaign.

AAP

Mahathir returned to the position of prime minister this year after a surprising electoral victory, saying he would remain in power only two years before handing over the reins to Anwar.

Anwar was in prison when he forged an unlikely alliance with Mahathir in an attempt to oust the then Prime Minister Najib Razak, who called for elections in May amid accusations of massive corruption.

Underscoring the drama of Saturday's vote, one of Anwar's six challengers is a former aide who also accused the then opposition leader of sodomy, and took a 71-year-old person to jail for the second time in 2014.

But the charismatic politician is expected to achieve an easy victory in the seat, which was left unoccupied after a member of the ruling coalition withdrew to prepare for Anwar's return.

Ballot boxes opened under cloudy skies at 8:00 am (0000 GMT) in the sleepy coastal town south of Port Dickson, home to a large ethnic Chinese community that has traditionally been one of the pillars of the nation's history. Anwar support.

"We are voting for the next prime minister, we need an influential leader to achieve long-term progress in Port Dickson," said 60-year-old voter Lee Tian Hock.

"This morning, I prayed to Allah for a great victory for Anwar," retired truck driver Mat Taib, a member of the country's ethnic Malay majority, told AFP.

"I want him to be our eighth prime minister."

Some 100 supporters greeted Anwar with shouts of "Reformasi", his battle boss while in opposition, when he arrived at a polling station.

"Voter turnout is too slow, hopefully, more will emerge to cast their votes after they finish their work in hotels and factories," he said.

"I'll see you in parliament on Monday," he told an AFP reporter with a broad smile.

Supporters travel with flags of Pakatan Harapan (Alliance of Hope).

AAP

Charismatic politician

Anwar campaigned hard in the last two weeks to secure a mandate in the multiracial constituency, promising voter development, clean government and a boost to local tourism.

He has not discussed the accusations of sodomy, an act that remains largely illegal in Muslim Malaysia, while he was in the election campaign. He has always maintained that the charges were invented to derail his political career.

But he has campaigned tenaciously on the billionaire scandal at the 1MDB state fund, over which former leader Najib and his wife Rosmah Mansor face dozens of corruption charges.

Both face the possibility of spending the rest of their lives in jail in a scandal that caused the Najib coalition to lose office for the first time since the country declared independence from Britain in 1957.

Rosmah Mansor, the wife of former Malaysian Prime Minister Najib Razak, arrives at the Kuala Lumpur High Court in Kuala Lumpur, Malaysia, on Thursday, October 4, 2018.

AAP

The political heavyweights, including Mahathir, have campaigned for Anwar on a way back to the office that was unthinkable even six months ago.

The duo took the stage together at a campaign event, prompting applause from supporters.

After he was abandoned as finance minister and imprisoned in the 1990s, Anwar led a reformist opposition movement while struggling to overturn his convictions.

Mahathir, his mentor turned tormentor and now ally, returned from retirement to lead the coalition of the Alliance of Hope that won power in May.