The big guns are going at each other in Westminster over the issue of relaxed immigration.
The Home Secretary, Theresa May, is in denial over the relaxation of immigration rules. "A big boy did it and ran away" is her defence. In this case, the big boy in question is Brodie Clark, the former Borders Chief, and he has certainly not run away, having stated he intends to lodge a constructive dismissal case, something he is likely to win.
The question that must be asked is how responsible is a cabinet minister for the actions within their department. If Brodie Clark was acting outwith procedures, then it could be reasonable argued that she cannot be expected to know every detail of what is happening, especially if it is not reported to her. Ministers receive high level reports, and only get a drilldown of the facts when an investigation is warranted. This applies to all departments.
However, it could also be argued that with such a serious issue as immigration controls being relaxed, and potentially allowing all manner of undesireables into the country, then her ignorance is no defence.
The Shadow Home Secretary Yvette Cooper seems to be using this line of attack, and it is getting results. The Prime Minister is once again being forced to defend a minister, and stating that they have "his complete confidence" (ie she'll be gone soon!).
It is an interesting situation, and we saw a similar episode with Stewart Stevenson last December in Scotland.
What it boils down to is confidence. If Parliament - not the Government of the day - does not have confidence in a minister's abilities to do the job, then that minister must resign. To hang onto office merely amplifies the problems and is a distraction to finding a solution to the problem.
Prime Ministers and First Ministers do not like forcing ministers to resign, usually because they are political allies within their own parties. But loyalty has a limit - the country comes first.