DAP supremo Lim Kit Siang has called for a ceasefire on public bickering between Pakatan Harapan members.

Lim said while freedom of speech should not be restricted, it should not undermine unity within the coalition.

"I fully agree with Bersatu strategist Rais Hussin’s warning against friendly fire among Harapan politicians, as it could lead to negative perceptions and awful consequences for Pakatan Harapan.

"(As such) I call on all Harapan leaders to stop making any overt attacks on leaders of other Harapan parties without first discussing and getting (the) green light from their own parties," he said in a statement today.

He said a standard operating procedure should be drawn up for Harapan leaders to criticise one another.

He said if the SOP is not satisfactory, then the Harapan presidential council can step in and formulate a better mechanism.

Harapan leaders have been trading barbs with one another over various issues.

One of the internal battles being fought now is over whether de facto unity minister P Waythamoorthy should resign following the death of firefighter Muhammad Adib Mohd Kassim.