The United Party for National Development (UPND) has suspended its Namwala MP for opposing the pact with the Patriotic Front (PF).
UPND spokesperson Charles Kakoma has announced that Robby Chizuka has been given seven days to exculpate himself.
Major Chizuka is accused of issuing derogatory statements against PF leader Michael Sata.
He is also accused of organising UPND members to reject the pact between the two parties.
Kakoma says this amo0unts to gross indiscipline.
The UPND and PF tomorrow are expected to hold a joint rally in Lusaka.