The only immigration policy seems to be covering up some unpalatable truths

Whether ministers like it or not, democratic accountability makes them the ultimate fall-guys

It is a tribute to the shadow Home Secretary David Davis that it was to him, rather than to a newspaper, that James Cameron, the British consul in Romania, turned to reveal the devastating contents of his e-mail concerning bogus immigration applicants. The fact that contacting a shadow minister is now seen as the most effective way of raising an issue of public concern is a compliment to the sharpness of Michael Howard's frontbench team and a personal scoop for Mr Davis following his earlier efforts to call Home Office ministers to account.

It is a tribute to the shadow Home Secretary David Davis that it was to him, rather than to a newspaper, that James Cameron, the British consul in Romania, turned to reveal the devastating contents of his e-mail concerning bogus immigration applicants. The fact that contacting a shadow minister is now seen as the most effective way of raising an issue of public concern is a compliment to the sharpness of Michael Howard's frontbench team and a personal scoop for Mr Davis following his earlier efforts to call Home Office ministers to account.

This has been a good month, not only for Mr Davis, but also for the rest of his Home Affairs team - thanks to the excellent delegation of aspects of his brief to the competent spokesmen and women in his team. Julie Kirkbride, the savvy spokeswoman on the media, has steered the Tories from being anti-BBC. Alan Duncan has been preparing an effective gay-friendly response to today's publication of the Civil Partnerships Bill, while Dominic Grieve made the running on the case for publishing the Attorney General's advice on the Iraq war.

This effective delegation has ensured that, unlike Beverley Hughes, who received e-mails from officials that went unread, Mr Davis has had the time to digest and recognise the significance of the anonymous e-mail, which, it turned out, came from Mr Cameron and proved to be such political dynamite.

At first, many were apprehensive about the Tories relying on the original evidence, submitted to The Sunday Times by Steven Moxon, the junior official in the Sheffield branch of the Immigration and Nationality Department. Labour lost no time in smearing him by trying to undermine his character with suggestions that he was anti-Muslim, suggestions which he has strongly denied. There were dark hints suggesting that Mr Davis had been wrong to get too close to Mr Moxon when he made his allegations about procedures for fast-tracking immigration applications at the Sheffield branch of the Home Office.

But Mr Davis is not easily browbeaten and those that try this tack forget that his early training as an SAS reservist taught him never to be intimidated when under fire. He knew that he was on to something right from the start. Either Ms Hughes was incompetent for not knowing what sections of her department were doing, or she knew far more than she was letting on and was guilty of misleading Parliament. When she relied, for her defence, on attacking civil servants in her private office, Mr Davis immediately smelt a rat. Among his former ministerial posts in government was a junior position in the Cabinet office responsible for the Civil Service. This instilled in him an old-fashioned view that ministers should never blame, publicly, civil servants and that the buck should stop with the politicians.

Ms Hughes must be bitterly regretting that the internal inquiry that exonerated her was so limited in scope that its findings are being drowned out by the latest disclosures. This has ensured that there is a further breakdown in trust between her and officials further down the line of management. The likelihood of more whistle-blowers coming forward has increased rather than diminished. It says something about our culture of public service, and its honesty and integrity, that officials are prepared to take risks with their career prospects, albeit under the dangerous cloak of anonymity.

Once again, the issue of trust concerning this Government is raised in the public mind. The suspicion grows that there is actually no immigration policy except that of the cover-up, reinforced by the suspension of good guys who tell the truth, while ministers equivocate to save their own careers. The brutal attempts to smear Mr Moxon, appeared, momentarily, to work but Mr Cameron's status and the seriousness of his allegations are far more serious. If Ms Hughes relies again on the defence that she did not know what was going on, her political future must eventually be in doubt.

This saga raises once more the extent to which the dictum of ministerial responsibility and accountability should result in political resignations. We cannot yet be satisfied that the confusion in the Immigration and Nationality Department is solely the fault of civil servants. My own experience of dealings with officials, as the government's Transport and Northern Ireland whip, a decade ago, led me to conclude that it was usually civil servants who cleared up the mess left by us, their political masters, rather than the other way round.

Honesty and integrity are, even under this Government, still the hallmarks of the culture of public service; but ministers are less willing to hear necessary words of caution and warnings from senior civil servants. The culture of "No Minister'', which was once as significant as "Yes Minister'', seems to have been lost.

But restraining ministers is an essential quality of the Civil Service. If they are not actually being instructed to do things that are improper or even illegal, civil servants are certainly being put under subconscious pressure to cut corners, in the interests of politically motivated targets.

Perhaps the most serious aspect of the current furore was the release, by Mr Davis, of correspondence to officials at the Home Office, from Sir John Ramsden, the senior official at the Foreign Office, indicating that the Home Office was resisting and blatantly ignoring warnings of "an organised scam'' in Bucharest. Why? Presumably because of ministerial pressure to clear backlogs. It smacks of something like: "I don't care how you do it, Sir Humphrey; just do it.''

There is no doubt that senior management at the Home Office were made aware of operational shortcomings. Civil servants, no matter how high up the administrative ladder, do not have the authority to make up immigration policy without reference to ministers. Caution, the operation of rules, guidelines and procedures are the watchwords of the Civil Service at every level. That is why it is preposterous for ministers to claim ignorance as a defence.

But this is where the Government's tendency to politicisation of the highest grades causes damage. Senior civil servants are too often encouraged to read and anticipate ministers' minds and priorities, with half an eye on how this will enhance promotion prospects, rather than risk the opprobrium of appearing obstructive by giving dispassionate but unwelcome advice. And politically appointed special advisors can also be intimidating if they encounter perceived obstructions from those operating by the conventional book.

Whether ministers like it or not, democratic accountability makes them the ultimate fall-guys. That is what democracy is about. There is nothing fair about this process. However much ministers may be able to persuade us that they did not know or condone what was being done in their name misses the essential point. If they don't know what is going on, then what is the point of them in the first place?

mrbrown@pimlico.freeserve.co.uk