Kabila has rejected the suggestion out of hand. Not all that surprisingly. In fact, his people have rejected talks, saying that if he loses, Kabila will step down. Also, that if street protests become "too chaotic" for police, the army will be called in.
It is unclear who might have suggested Banda as mediator but apparently,
"He is just waiting for the UN to send a plane for him to travel. He has accepted to mediate," a spokesperson for Banda told Reuters, asking not to be named.