Media playback is unsupported on your device Media caption Alice Budisatrijo reports as Indonesia holds for elections

Indonesians have cast their ballots to elect representatives in national and local parliaments.

Some 19,000 seats are being contested across the nation, including the 560 seats in the national parliament.

The polls will determine which parties can field candidates for the presidential election on 9 July.

The opposition Democratic Party of Struggle is expected to do well. Its candidate, Joko Widodo, is seen by many as Indonesia's next president.

Mr Widodo, the Jakarta governor who is popularly known as Jokowi, has proven to be a hit with voters because of an approachable and down-to-earth image.

He told reporters at a polling station in Jakarta he believed his party would perform strongly.

"I'm very confident that my party will do very well,'' he said.

Analysis Some 235,000 candidates will compete for more than 19,000 seats in national and local parliaments. The vast majority of the 187 million Indonesians registered to vote will never have heard of most of the names on the ballots until they get to polling booths. That, and the general distrust and disappointment toward the past and current parliaments, will make voter turnout lower than in the presidential elections, due in July. But the legislative elections matter beyond determining who get to sit in parliament. The party that wins more than 25% of the popular vote or 20% of the 560 seats in the parliament will be allowed to field its own presidential candidate. Others will have to form a coalition. Until Jakarta Governor Joko Widodo, known here as Jokowi, announced his presidential bid last month, no party was believed to be able to meet the thresholds. But the party that supports the popular governor, the Indonesian Democratic Party of Struggle (PDIP), has since been polling above 20%. Surveys say the "Jokowi factor" may also help voter turnout. With almost one-third of the registered voters being first-time voters, Jokowi's popularity among young people is expected to drive more of them to the polls.

Voting is taking place across three different time zones, however, election officials have already warned of possible delays with the vote.

One official for Papua province, Betty Wanane, told the AFP news agency that planes carrying ballots could not reach dozens of districts in mountainous areas, warning of delays of up to three days.

Corruption scandals

Parties wishing to field candidates in the presidential polls must either secure 20% of the seats in parliament or 25% of the total vote.

Candidates whose parties fail to meet these thresholds must form or enter a coalition before they can run for president.

The ruling Democratic Party of Indonesian President Susilo Bambang Yudhoyono is expected to see its support fall, amid a raft of corruption scandals.

Mr Yudhoyono, meanwhile, is constitutionally barred from seeking a third presidential term.

Mr Widodo's main challengers are currently expected to be businessman Aburizal Bakrie of Golkar - one of Indonesia's largest and oldest political parties - and former military general Prabowo Subianto of the Gerindra party.

Image copyright Getty Images Image caption Election officers prayed at a Denpasar temple before opening polling stations in Bali

Image copyright AFP Image caption Mr Widodo said he was "very confident" of his party's chances

Image copyright AFP Image caption The polls will dictate which parties can field candidates for the presidency

Indonesia is the world's largest Muslim nation and South East Asia's biggest economy.

Some 187 million Indonesians are eligible to vote, with nearly 22 million people voting for the first time.

The country has declared Wednesday a public holiday to encourage high voter turn-out.

The polls are expected to be largely peaceful despite fears of violence in the western Aceh province following a series of politically-linked attacks last week.