Former premier Mahathir Mohamad and opposition stalwart Lim Kit Siang spent nearly two hours on Tuesday night fielding searching questions from an audience of about 200 young people, as they attempted to engage a crucial vote bank that is apparently losing interest in politics.
The veteran duo shared a sofa in Petaling Jaya, Kuala Lumpur's satellite city which has been an opposition stronghold over the past decade - a period during which the Umno-led Barisan Nasional (BN) lost its customary two-thirds control of Parliament, and subsequently the popular vote majority, for the first time.
But the opposition's recent electoral successes could be reversed if it fails to revitalise voters below the age of 40, who have been more inclined to vote against Prime Minister Najib Razak's government in previous polls.
A survey by top pollster Merdeka Center in August found that seven in 10 voters below the age of 30 did not care about politics and believed politicians were not trustworthy. The Election Commission has also revealed that two-thirds of unregistered voters are below the age of 30. As of June, 3.8 million eligible Malaysians have yet to register - more than 25 per cent of the 14.6 million who have enrolled.
"Tun (Dr Mahathir) and I belong to the 5 per cent, facing the 95 per cent who are the future of the country," said Mr Lim at the "WhatSayYouth" town hall forum.
Despite younger leaders rising through opposition ranks compared with those in BN, Dr Mahathir, 92, and Democratic Action Party (DAP) supremo Lim, 76, remain Harapan's most recognisable faces.
Dr Mahathir left Umno after failing to get the long-ruling party to ditch Datuk Seri Najib over billion-dollar allegations of graft in the 1Malaysia Development Berhad (1MDB) scandal.
But while the opposition welcomed him as an asset to boost flagging support among the Malay majority, many young voters are still sceptical of the man whose 22-year rule was marked by claims of abuse of power and financial scandal - many of which were fodder for Mr Lim's attacks against the Mahathir administration that ended in 2003.
Issues such as the 1987 Operation Lalang dragnet that saw 106 people, including Mr Lim, detained without trial, central bank foreign exchange losses amounting to tens of billions of ringgit, and accusations that Dr Mahathir undermined the independence of institutions such as the judiciary and police - often cited as the reason why Mr Najib has not had to answer for 1MDB in court - took centre stage at the town hall.
"People like to say it is because you instituted this system, therefore there is corruption and kleptocracy. But if it is because of me, why is it that during my time there was no such movement among the people to get rid of me?" Dr Mahathir said, pointing out that he won more than two-thirds of Parliament in all five elections as Prime Minister.
Opposition supporter Tharmelinggem Pillai, 24, asked Mr Lim if Harapan came to power, "would you create a Royal Commission of Inquiry to investigate the misdoings of the past, for example the wealth of Tun Mahathir's sons... the BNM (Bank Negara) scandal. Or is it okay now that he is your partner?"
The Gelang Patah MP, who drew the most votes in DAP's recent polls, replied that "if there is perception of abuses of power, there should be a full investigation" but insisted that "the most important thing today is to bring about change".
Studies have shown that opposition parties fared better with younger voters. Data analytics firm Politweet found a drop-off in Malay support for the opposition among voters older than 40 at the 2013 general election. There was a Malay swing to the opposition up to age 36. Those older shifted to Barisan.