Lee Chean Chung is the latest senior PKR figure to walk away from the party, but his departure is no longer an isolated political dispute.
He is the fourth PKR lawmaker to leave the party in recent months, following former deputy president Rafizi Ramli, former vice-president Nik Nazmi Nik Ahmad and former Subang MP Wong Chen.
All four have now found themselves outside the party that once brought them into national politics, with Lee joining Bersama alongside Rafizi, Nik Nazmi and Wong.
For PKR, that makes Lee's departure more significant than the loss of a single MP.
Lee spent 18 years in PKR and held senior positions including treasurer-general and communications director.
He was elected Petaling Jaya MP in the 2022 general election after previously serving two terms as the Semambu assemblyman in Pahang.
But his relationship with the party had been deteriorating for months.
The tensions became more visible after Lee attended the launch of Bersama in May, despite remaining a PKR member.
He later resigned from PKR's central leadership council in June, although he initially said he would remain with the party and continue serving as Petaling Jaya MP until Parliament was dissolved.
Lee had also raised disagreements over several government policies, including the Urban Renewal Act, migrant worker recruitment and the sales and service tax.
He questioned whether being part of a unity government justified what he regarded as political compromises.
The breaking point came on Sept 30, when PKR suspended Lee's membership for three years.
Two days later, he resigned as Petaling Jaya MP.
On Monday, he formally left PKR and joined Bersama, where he has been placed in the party's interim leadership and given responsibility for helping lead its Melaka election campaign, particularly in building its machinery in Chinese-majority areas.
That makes Bersama increasingly difficult to separate from the story of PKR's departures.
The party, led by former PKR leaders including Rafizi and Nik Nazmi, is becoming the political home for several figures who once occupied important positions within PKR.
Lee's arrival adds another experienced organiser and former senior party leader to its ranks.
For PKR, meanwhile, the question is no longer simply why one of its members left.
Why are so many of its own senior figures now choosing to leave?
The departures do not necessarily point to one single cause. Each politician has had their own disagreements and circumstances.
But taken together, they show a widening political distance between some former PKR leaders and the party's current direction.
Lee himself described the broader political landscape as being in a period of “disintegration” and criticised what he saw as political platforms cooperating publicly while working against one another behind the scenes.
There is also a more immediate consequence.
Lee's resignation leaves Petaling Jaya without an MP, and the Election Commission has confirmed that no by-election will be held.
Under Article 54(1) of the Federal Constitution, a parliamentary vacancy occurring within two years of Parliament's automatic dissolution does not have to be filled unless the Speaker determines that it affects the government's majority.
Petaling Jaya now joins Pandan, Setiawangsa and Subang as parliamentary constituencies without a sitting MP.
So Lee's departure leaves PKR with a political problem, Bersama with another prominent recruit, and Petaling Jaya voters without a parliamentary representative for the remainder of the term.
The bigger question for PKR is whether these departures remain a series of individual disagreements or whether they reflect a deeper struggle over what the party is supposed to represent as the next general election approaches.