Expat Indonesians living in Australia have lined up for hours to vote in their country's election, with an estimated 15,000 casting their ballots at Indonesia's consulate in Melbourne, according to the Indonesian Overseas Election Committee.

Key points: Many Indonesians in Australia are first-time voters and waited for hours to cast their ballots

Many Indonesians in Australia are first-time voters and waited for hours to cast their ballots Thousands did not register in advance, but decided to vote to determine their country's future

Thousands did not register in advance, but decided to vote to determine their country's future They said corruption, protections for minorities, and effective governance are key issues

About two million Indonesian eligible voters live overseas, including 65,000 in Australia. They vote a few days before their country officially goes to the polls on Wednesday.

Many Indonesians in Australia are students and first-time voters in an election that pits President Joko 'Jokowi' Widodo against former General Prabowo Subianto for the second time.

The two men last went head to head in the 2014 presidential campaign, which saw former Jakarta mayor Jokowi sweep to power, but the contest is much closer this time around.

People queued for hours in Melbourne to vote in Indonesia's election. ( ABC News: Sean Mantesso )

Among those waiting to cast their vote on Saturday was Albert Witanto, a student in Melbourne who described this year's election as "a very tight competition, just like when Trump was head to head with Clinton".

It is the 22-year-old's first time voting in an election and though he said he feels nervous about the outcome, he has high hopes for his country's future.

"I hope that Indonesia will grow and expand more rapidly and create a more effective government," he told the ABC.

Siauw Exel Prasadhana Setiawan, another Melbourne-based student, said he and his family had initially had deep discussions about whether to vote or not, since "both of the presidential candidates have their own flaws".

Although they live in Australia, many members of the Indonesian community are engaged with politics back home. ( ABC News: Sean Mantesso )

While it is highly unlikely that the leader of the world's largest Muslim nation can solve all the country's issues in a single five-year term, Mr Setiawan wants a leader who can tackle corruption and environmental mismanagement, as well as improve protections for minorities.

As the influence of conservative Islamic groups has grown during Jokowi's tenure, there has been a string of high-profile blasphemy cases targeting religious minorities, including the conviction of Buddhist woman who complained about the volume of mosque loudspeakers.

But Prabowo is seen as the more hardline candidate, and has the backing of conservative Islamic political parties.

More than 193 million voters will go to the polls in Indonesia on Wednesday, making it the world's biggest direct presidential election.

While there were no Australian-style "democracy sausages", popular Indonesian dishes such as satay were being sold to hungry voters. ( ABC News: Sean Mantesso )

They will also elect more than 20,000 parliamentary and legislative members in national and local-level positions contested by more than 245,000 candidates.

In Melbourne, the large number of voters caused some traffic disruptions outside the consulate, with lines stretching for hundreds of metres.

Much of that was due to about 2,000 people failing to register online ahead of time. They were asked to register on Saturday morning and return to vote an hour before the polls close at 7:00pm.

Anggraini Prawira, who registered online and skipped the queues, said she was surprised to see a much bigger crowd than at the last election.

"Everyone is so enthusiastic to come and to see … and we want to vote, we want the best for Indonesia," she said.

"Even though we live in Australia, we do really care what has been happening in Indonesia."

The election has been causing divisions among Indonesians, with many facing blowback for their political choices from their families and friends.

But Ms Prawira said she expected that the election would run peacefully and the outcome would be respected by all sides — whoever wins.