Why Clarke should go:
He's responsible for a shambolic department;
His department's screw-up has put public safety at risk;
He was more concerned with downplaying the screw-up than fixing it - until he was caught out and even now the full facts have not been disclosed;
Only a resignation will demonstrate that the government takes public safety seriously.
Why Prescott shoud go:
He brought his office into disrepute (made it a laughing-stock);
He has flouted duty of care towards a subordinate - if he were in uniform he would be court-martialled;
His actions are in flagrant disregard of equal opportunities training;
He has indulged his affair using government resources;
He cannot be trusted or viewed with any credibility at all.
Why Bliar shoud go:
Presiding over a shambolic government;
Lying over Iraq (I can revisit that argument if required);
Making a catastrophic misjudgement in following Dubya's lunacy;
He ignores the sacrifices of the Armed Forces by refusing to visit the wounded and bereaved;
The public simply do not trust him and would not permit him to direct the use of military force in any future conflict.
We need a "Ministerial Office Test" that mirrors the "Service Test" and has similar stringent consequences for transgression.