It occurs to me that Mthemba and Mantashe may be playing a similar game, both are at the forefront of the call to seriously discipline ANC MPs that dare to vote with their conscience and not tow the party line. Surely this makes it  increasingly difficult for the speaker to justify an open vote.  Both have in the resent past made comments that would not be considered to be towing the party line. Perhaps their aim is to force a secret ballot with plausible deniability?