BN's victory in the Sungai Besar and Kuala Kangsar by-elections made Najib arrogant and rapacious, and emboldened him to move against his opponents, said Gerakan Ketua Cawangan Malaysia (GKCM).
GKCM president Kamarul Azman, who leads Umno branch leaders opposed to Najib, said this in response to the Umno supreme council's sacking of Umno deputy president Muhyiddin Yassin and supreme council member Mukhriz Mahathir from the party yesterday.
Umno vice-president Shafie Apdal, another critic of Najib, was also suspended.
"It is clear that the results of the Sungai Besar and Kuala Kangsar by-elections made Najib and his accomplices arrogant and rapacious.
"Najib and his accomplices are feeling more confident after the recently concluded twin by-elections…," he said in a statement today.
Kamarul, who sarcastically described Umno as ‘United Mohd Najib Organisation’, described the axing of two senior Umno leaders as a black mark in the party's history.
"The sackings were the strangest in Umno (history) or even in any party.
"Never before members are sacked or suspended not for their wrongdoings but for voicing out against the wrongdoing of leaders," he said.
Kamarul warned of a "time bomb" that would explode in the 14th general election.
"They (the people) will teach BN a lesson in the 14th general election. It is like a volcano waiting to erupt," he said.
The Umno supreme council yesterday unanimously sacked Muhyiddin and Mukhriz as well as suspended Shafie on disciplinary grounds.
Najib also announced that the government would cut funding to Perdana Leadership Foundation, an organisation led by former premier Dr Mahathir Mohamad.
Mahathir and his allies accused Najib of corruption and have vowed to unseat him as prime minister. Najib denied any wrongdoing.