Simmering tensions within the opposition have gone up a notch after the lightning move last Friday to endorse erstwhile enemy Mahathir Mohamad's "Citizens' Declaration" that brought several Umno and former government figures together with prominent civil activists in a joint battle against Prime Minister Najib Razak.
While several top opposition leaders were in attendance, such as Democratic Action Party (DAP) supremo Lim Kit Siang and Amanah president Mohamad Sabu, there were prominent absentees from Parti Keadilan Rakyat (PKR).
Sources told The Straits Times that the party is split over whether to place all bets on a change of government, or to hedge on winning a general election that must be called by 2018.
PKR deputy president Azmin Ali and vice-president Tian Chua were at the unprecedented event where the former sat next to Tun Dr Mahathir.
But despite the support by jailed opposition chief Anwar Ibrahim for the collaboration from behind bars, his wife Wan Azizah Wan Ismail and daughter Nurul Izzah - the PKR president and vice-president, respectively - were conspicuous by their absence.
Datuk Seri Wan Azizah is insisting that although it was not explicitly stated in the declaration, freeing her husband from a sodomy conviction is "one of the biggest reforms" that the 45 signatories must pursue .
Such a demand complicates the campaign to remove Datuk Seri Najib which is focused on allegations of graft involving around US$700 million (S$970 million) linked to state investor 1Malaysia Development Berhad (1MDB).
A strategist in Dr Wan Azizah's camp told The Straits Times that they are taking the long-term view of sticking to their guns on issues of government abuse.
"It's very unlikely to get enough MPs to vote out Najib. So it's important to show Mahathir is with us, rather than the other way around. That gets us a 4 to 5 per cent jump in Malay votes which could be enough to win the elections," the source said.
Mr Azmin and his allies have long shown their ability to work across political differences.
His government in Selangor still has the support of Parti Islam SeMalaysia, despite the Islamic party parting ways with the wider opposition after a split last year.
Speculation has been rife since last year that if Umno deputy president Muhyiddin Yassin - who was sacked as deputy prime minister last year - were to take over the federal government, Mr Azmin would be deputy prime minister.
However, some segments in the DAP, which has the largest block of opposition MPs, are guarded over Mr Azmin's rise to national prominence in the past two years.