The latest turn of events has seen the NAO admit that it has made accounting errors of its own.

The NAO conceded that it had not separately recorded Sir John’s wife’s chits and the associated tax payments paid by the NAO, which should have been reported as part of Sir John’s remuneration.

This, public sector readers will need no reminding, is the body that ever so delicately highlights the smallest of problems in government accounts to devastating effect.

Can Sir John realistically continue as the chief of an organisation entrusted with keeping a close eye on government spending when his organisation can’t seem to keep a handle on his own, some people will be asking.

Can the NAO maintain its high moral tone in scrutinising important topics like the budget for the 2012 Olympics and the new pay contracts for GPs working in the NHS, when it has had to admit its own book- keeping is flawed?

The answer, surely, is no.

Last week, it seemed that the final squalls of Sir John’s damaging expense account storm had broken when the Commons’ Public Accounts Commission said that the NAO boss would have to suffer having his expenses vetted by an independent figure.

The latest act in the Bourn saga looks like it ought really to involve Sir John and the NAO going their separate ways.

If Whitehall concludes that there is no problem in him remaining, the sense that there is a culture of whitewashing in Whitehall may take deeper root.

David Jetuah is a reporter on Accountancy Age