The Constitution is crystal clear on the matter. Najib, having been convicted is automatically disqualified from membership of the Legislative Assembly. No ifs ands or buts. Nothing in the Constitution about appeals, stays of execution or any other legal get outs. If there were such he could use them. But there are not.
His conviction bars him from membership of the Assembly and that is that. So why does the Speaker not act? Why does Prime Minister Moo appear to think that his personal wishes are superior to the Constitution? Because it has been manipulated to place him where he is? Because it is only the supreme law of the land and does not apply to mega criminals like Najib or those who ignore the Constitution whenever it suits them to do so: (and not all of them are in the Assembly).
Either the rule of law prevails or Malaysia is an illegal dictatorship. Which is it to be Moo? And puppet master.