When Dr Mahathir Mohamad quit Umno yesterday, all eyes focused on whether he will lead a campaign against Prime Minister Abdul Razak in cooperation with the opposition, and possibly even civil society joining in.

If everything goes on smoothly for Mahathir and the opposition, political commentator Josh Hong expects, in the next general election two years down the road, a coalition or alliance that matches the ruling BN to be established.

Several conditions are needed to strengthen the anti-Najib campaign so that it can weaken the BN led by Najib, Hong said.

These conditions include both Mahathir and opposition ironing out their terms for co-operation, plus other heavyweight leaders in Umno and BN supporting their efforts.

"From what I see, every time Mahathir runs into a dead alley, he will come out with something dramatic," Hong ( photo ) said, referring to Mahathir's decisions to quit the party in 2008, and again yesterday.

"Do not overestimate Mahathir's influence. He wasn't left with much choice and he doesn't have much advantage now (as compared in 2008, when he first exited Umno)," he said.

The country's longest serving prime minister would need to rely on the opposition, particularly on the green-light from his long-time rival and PKR de facto leader Anwar Ibrahim, to form an anti-Najib coalition, he added.

Despite a warm reaction from DAP veteran leader Lim Kit Siang and PKR deputy president Azmin Ali, the nine-month old Pakatan Harapan and its allies have yet to come out with a stand on working with Mahathir.

Mahathir only wants Najib to step down while the opposition has repeatedly demanded for a total change of the system.

If Mahathir stands firm in only wanting to change Najib, then the jailed PKR de facto leader may not work with him, noted Hong who is also a Malaysiakini columnist.

"Even if they settle their differences and work together, they still need the support of heavyweight leaders in BN and Umno, such as suspended deputy president Muhyiddin Yassin, vice-president Shafie Apdal and veteran Tengku Razaleigh Hamzah," he added.

Najib's trump card

Only then can the anti-Najib coalition affect BN badly enough before the next general election, though Najib would remain unshakable for the time being.

"And why did I mention the Umno veterans? Razaleigh is pretty much a symbol to the the hardcore and middle-class Malays who distrust both Najib and PAS but think that the veterans like Razaleigh and Mahathir are moderate nationalists," Hong explained.

"And from what I see, PAS is Najib's trump card. There is a chance PAS may work with Umno. PAS has its own hardcore supporters," he said.

PAS would think twice in supporting Umno if the anti-Najib coalition builds up its momentum, said Hong, adding 'the low morale' opposition coalition needs Mahathir more than Umno does.

"It is pretty ironic that the opposition needs a leader to lead them. In the past, they needed Anwar, now they need Mahathir," said Hong.

The last time Mahathir exited Umno saw then Prime Minister Abdullah Ahmad Badawi step down a short while later.

"Several reasons led to Pak Lah to exit politics,” recalled Hong. “First, Umno wanted to get rid of him following the 2008 general election setback, which saw the BN being denied its two-thirds majority in Parliament.

"Also, Abdullah had a good successor - Najib. Now, you don't have one to replace Najib. Deputy Prime Minister and Umno vice-president Ahmad Zahid Hamidi is with Najib.

“Mahathir dislikes leaders like Hishamuddin Hussein and Khairy Jamaluddin. They do not trust Mahathir either," he said.

"Najib is pretty much a fighter himself and he just uses the machinery (to retain power). He had the former attorney-general Abdul Gani Patail replaced, irregardless of criticism," Hong added.

Umno does not see Najib as a betrayer, for Umno won more seats in the 2013 general election, if compared with Abdullah's era, he said.

Asked about the March 27 'oust Najib' gathering called by former law minister Zaid Ibrahim, Hong said its success would depend on Mahathir and the opposition parties.

He said he personally does not see Zaid as leading the 'closed door' event.

He also pointed out the organisers risked angering Catholics as they will be celebrating Easter on March 27. "So, it is better for them to change the gathering date," he said.

Another observer, the executive director of independent pollster Merdeka Center, Ibrahim Suffian , said that Najib and his party would not suffer any far-reaching consequences for now.

Mahathir won't have an effect

"In the short-term, any negative impact on Umno and Najib will be limited. They will solve the problem they are facing," Ibrahim said.

In the medium-term, he said, Mahathir could galvanise public opinion further against Najib and the government.

It would also be difficultfor the administration to win back support lost by the slowing economy and the various controversies that it is embroiled in, Ibrahim ( photo ) added.

"If Mahathir mobilises the dissenting elements in Malaysian politics, this move would signal that he is taking his case to the electorate, rather than to Umno members.

"If he is successful, he could split the Malay-Muslim vote, which forms the backbone of support for the ruling party in Malaysia," noted Ibrahim.

Whether Mahathir would lead the opposition in his anti-Najib campaign up to the next general election would depend on how things develop from here on, he added.

Meanwhile, National Defence University’s Prof Aruna Gopinath said Mahathir leaving Umno meant that he had more room to oust Najib.

However, Aruna said, whatever Mahathir does would not gain traction as Malaysians have lost faith in the former prime minister.

"Once you are out of politics, you should not interfere. Mahathir has been interfering too much, in the sense that he tried to provoke (the people to topple Najib)," she said.

"He should retire, like Abdullah Ahmad Badawi. Mahathir thinks that he has a large following but I don't think the people will give him due respect," she added.

Asked about Mahathir voicing his concern over Najib's RM2.6 billion donation affair and the 1MDB fiasco, Aruna said Mahathir was only harping on these issues without evidence.

"Without evidence, you cannot simply talk about it. It is wrong to speculate. Unless you have evidence, then it will be different," she said.

"Only Najib knows the truth," she added.