Bersatu supreme council member Wan Saiful Wan Jan has cautioned PKR against spreading its disease to others in Pakatan Harapan.
The academic-turned-politician also called on those in Harapan to refrain from making slanderous and wild allegations.
He said while making such claims could be the culture of other parties, Bersatu chairperson Dr Mahathir Mohanmad, however, had taught members to respect Pakatan Harapan's spirit of solidarity.
"As we (in Bersatu) show respect for the friendship forged, there must not be leaders from other parties who spread slander due to their desire for positions.
"This immoral behaviour is not a culture that we want to shape within the Harapan pact,” he added in a media statement this afternoon.
Wan Saiful was commenting on the claim that PKR deputy president Azmin Ali is colluding with Mahathir and Daim Zainuddin to prevent Anwar Ibrahim from becoming the next prime minister.
The accusation was made by PKR lawmaker Abdullah Sani Abdul Hamid. He is aligned to former Pandan MP Rafizi Ramli, who is contesting against Azmin for the number two post.
Wan Saiful said others should not be dragged into the internal rift of PKR and urged the party's leaders to be firm on such allegations.
“The leaders must prove they disagree with such insolent behaviour. Failing which, the people will consider that PKR's top leadership accepts slander and bad behaviour,” he added.
Anwar has since dismissed Abdullah's remarks as his personal views and urged candidates in the PKR polls not to indulge in personal attacks.