(ROUGH CUT - NO REPORTER NARRATION) Indonesia's presidential candidates cast their votes on Wednesday (April 17) in a battle to lead the world's third-largest democracy.

Incumbent Joko Widodo voted in presidential and parliamentary elections in Jakarta, hoping to be re-elected for a second term.

Widodo, a former furniture salesman who launched his political career as a small-city mayor, is standing for re-election in a contest with ex-general Prabowo Subianto, whom he narrowly defeated in 2014.

Prabowo is a 67-year-old former general taking on Widodo for the second time.

Prabowo has long harbored ambitions for the top job, but a lack of support meant he sat out the 2004 election, ran as vice president on a losing ticket in 2009 and was defeated by Widodo on 2014.

This time, Prabowo has consolidated support from hardline Islamist groups such as the Islamic Defenders Front (FPI) and religious parties, fueling concern about the influence of conservative Islam on future policy-making should he win.

Most opinion polls give Widodo a double-digit lead, but the opposition says the race is much closer and Prabowo said before voting in Bogor he was optimistic about winning with a big margin.

Unofficial "quick counts" will be released hours after polling ends and the winning presidential candidate is expected to be apparent by late Wednesday.

The General Election Commission is expected to announce an official result in May.