JAKARTA: Indonesia's ruling party on Friday endorsed provincial governor Ganjar Pranowo as its candidate for the presidency, an expected move backed by popular incumbent Joko Widodo, who will leave office next year after a decade in power.

Ganjar, governor of one of Indonesia's most populous provinces, Central Java, has been the frontrunner in several opinion polls this year and goes up against former Jakarta governor Anies Baswedan and ex-special forces commander Prabowo Subianto, in what is expected to be a hotly contested race.

The announcement by the Indonesian Democratic Party of Struggle (PDIP), which leads the ruling coalition, should put paid to persistent speculation that the president could seek to prolong his stay in office beyond his two-term limit, a scenario he has ruled out.

"Ganjar is a leader who is close to the people. Always meeting people and is very ideological," Jokowi, as the president is known, said during the party's announcement.

He emphasised the importance of a transition of power that was democratic.

Governor of Central Java since 2013, Ganjar, 54, is among a generation of provincial leaders from outside of Indonesia's political elite that has built its voter base on a track record of reform, efficiency and transparency.

But Ganjar saw his popularity dip this month after he backed another governor's call to stop Israel from taking part in next month's under-20 World Cup, which Muslim-majority Indonesia was due to host.

It was subsequently dropped as host by soccer's world governing body FIFA subsequently, leaving fans and players dismayed.

Accepting the party's nomination, Ganjar acknowledged the challenges ahead and said he was honoured to be picked to run for the top job in the world's third-largest democracy.

"I can do it and will fight as Indonesia's presidential candidate," he said.

"I was born in this party, moulded by this party, and grew up in this party," he added.

A survey by Indikator Politik released in April showed twice-defeated presidential hopeful Prabowo had taken a five-point lead over Ganjar, whose popularity declined after the World Cup fracas.

The poll showed Prabowo with the backing of 32% of respondents while Ganjar and Anies got 28% and 22% respectively.