The instruction to members of parliament by the ANC NEC or whip on how to vote, is unlawful in the first instance. The oath of office taken by an MP is not simply a personal promise. It is legally binding on that MP in his/her personal capacity. Voting in accordance with such oath is a legal obligation and failure to do so in fact unlawful. An instruction by the ANC to vote in any other manner is therefor an instruction to brake the law. Such instruction is not only unenforcable. Any MP who voted not according to the promise that underly such oath, but in compliance with the unlawful instruction, would be liable for the breach of a legally binding obligation.
Maybe some law guru may start asking questions whether MP's, particularly those advocating and threatening in public firstly complied with the legal obligation to vote according to the constitution. Secondly whether the threat of discipline by the party is not a criminal offence. Zuma may be holding a ticking grenade in his hands.