As PKR and certain Umno factions continue to toy with a possible collaboration ahead of the 15th general election (GE15), a Pakatan Harapan leader has warned that this could chip away at the coalition's support base.

Newly-minted Harapan Youth chief Shazni Munir Mohd Ithnin said any cooperation with Umno, before or after GE15, must not involve the "court cluster" of leaders facing graft charges.

"How do you justify this? For years we fought corruption and abuse of power, but suddenly when we are facing the election, or after the election, we work with these sorts of people.

"What do we tell the people, who all this while supported and believed in our reform agenda?" Shazni told Malaysiakini during an interview on Tuesday.