I think one of the main issues the electorate has with its MP's over the expenses fiasco is their wilful refusal to accept the moral responsibility of their actions, instead bleating that they acted 'within the rules'. As the oft used phrase has it - "Free speech does not entitle you to shout 'Fire!' in a crowded theatre."
Since is is finally, and reluactnatly dawning on the Honourable Members that the public is not simply going to do as it's told and mind its own business, they had better get off their collective backsides and be seen to do something.
Removwl of Martin would send the message that MP's acknowledge his disgraceful and immoral complicity in the whole affair, and that they intend to get their House in orer, albeit very slowly and reluctantly.
Apart from his role in this affair, Speaker Martin has proved himself unsuitable for his role, being arrongant, rude, vain, insulting, duplicitous, mealy-mouthed, and downright useless at his job. Thus, voting him out will enable MP's to enjoy the double whammy of looking tough and righteous, as well as shifting the pompous oaf out of his powerful position.
Speaker Martin should learn the lessons Margaret Thatcher failed to heed - listen to your colleagues, be nice, see the way the wind is blowing, go with dignity.
Since like Thatcher, Martin is utterly incapable of even seeing, much less understanding anyone's point of view except his own, this would be a good time to jump, but of course,as she was, he will have to be pushed.