The third debate between President Joko Widodo and his rival Prabowo Subianto ahead of elections next month did not disappoint, with both men taking a more combative stance as they locked horns over ideology, diplomacy, governance, defence and security.

In focus last night was the issue of governmental reforms, a key plank of Mr Joko's presidency and his campaign platform since he first entered politics 15 years ago.

The reform-minded leader repeated his pitch for bureaucratic reforms, including the need for more efficient e-governance.

Mr Joko, 57, who is running with prominent cleric Ma'ruf Amin, underlined the importance of utilising advanced digital technology to enhance electronic-based governance, proposing a tagline "dilan", which stands for "digital serves".

He also noted the need to speed up government services on the principle that speed is vital to future public services in one of the world's largest democracies.

"Reforms through electronic-based services are needed (in our bureaucracy). E-government, e-procurement to e-budgeting are very necessary to embrace the future digital era," he said.

Mr Joko also said his administration had closed down 23 government agencies in the more than four years of his tenure to reduce bureaucracy, and may continue the effort in future where necessary.

He added: "Electronic-based service is vital for speed. In the future, it will not be the strong countries that conquer the weak, but the fast ones that conquer the slow ones."

Mr Prabowo expressed a similar view, saying he and his running mate, former Jakarta deputy governor Sandiaga Uno, would also promote transparency through information technology.

"What we want to achieve is a government that is effective and free from corruption and IT is a great weapon that we can use to do that," he said.

He cited an example of using IT to boost the domestic tax ratio, which, according to Mr Prabowo, stands at 10 per cent, to 16 per cent.

Citing several non-cash welfare programmes issued by Mr Joko's administration, the challenger said: "We should also have a single ID card. There's no need to have too many cards."

Changing tack, Mr Prabowo said another big issue is that of domestic wealth stored overseas.

"Although we use sophisticated systems, what for if there's no political will from government to change our economic orientation? It's better to use old technology but our wealth stays at home."

His statement, which he conveyed in an emotional tone, elicited applause from the audience at the Shangri-La Hotel in Jakarta.

On foreign policy, both men, as expected, took a similar stance in their opening statements.

Mr Joko said that amid global instability and rising protectionism, Indonesia must continue with a free and proactive foreign policy.

Mr Prabowo said he would develop mutually beneficial relationships and defend the nation if elected.

The debate, however, took on a more fiery tone during a segment on national defence.

Mr Prabowo, a former three-star army general, lamented the poor state of the Indonesian armed forces, better known by the local acronym TNI.

"The strong will do what they can, the weak will suffer what they must," said Mr Prabowo, quoting Greek historian Thucydides, to emphasise his desire for a strong military. "I think Indonesia's defence is too weak because we don't have any funding as all of our money is flowing overseas, so how can we engage in diplomacy? We have no power," he added.

However, Mr Joko highlighted that Indonesia's defence budget is 107 trillion rupiah (S$10.2 billion), the second highest after the budget for the Public Works and Housing Ministry, which has driven the massive infrastructure push under his governance.

In response to the President's explanation, Mr Prabowo compared Indonesia's defence spending to Singapore's. "I'm sorry but I think Pak Jokowi was briefed wrongly on defence and security," said Mr Prabowo, referring to the President by his popular moniker.

"Our defence budget is only 1.5 per cent of our state budget, compared to Singapore where it is 30 per cent of their budget... And, Pak Jokowi, it's not that I have no faith in the TNI, I was in the TNI since I was 18. I'm more TNI than most in the TNI."

The previous debate was between the vice-presidential candidates. Last night's showdown was the last directly between Mr Joko and Mr Prabowo. The fifth and final debate, scheduled just days before polling day, will see them take on each other together with their respective running mates on April 13.