Nobody expects a straight answer these days. Dave Roberts, director of enforcement at the Immigration and Nationality Directorate (IND), told a committee of MPs that he had not the faintest idea how many illegal immigrants there were in Britain. The reaction to that naked truth was uproar. Maybe during our most recent stages of evolution human beings have lost the ability to cope with anything other than obfuscation.

Roberts was stating the obvious. Since some illegal immigrants entered clandestinely, we cannot know their numbers. Tony Blair made that point in the House of Commons a day later. He employed one of his favourite rhetorical devices by quoting Michael Howard who, as home secretary, had made the same self-evident observation.

Because the prime minister used a weaselly parliamentary trick to camouflage his ignorance, his performance was judged to be clever. Roberts remains condemned, like a man in a Bateman cartoon, for a serious lapse of decorum.

Roberts may be naive or simply an honest man. Perhaps he wanted to highlight the unreasonable position in which he and his colleagues are placed. The IND has never been given the resources needed to chase up asylum seekers whose applications fail, let alone to scour the country for people who arrive undetected on the back of a lorry.

Tony McNulty, the immigration minister, seemed to accept that there may be between 310,000 and 570,000 illegals in Britain. He said that it could take 10 years to process them if we dealt with 25,000 a year.

Even leaving aside his faulty arithmetic, it is a thoroughly misleading statement. We have no mechanism to track down those people and the government is not about to fund a massive increase in what it spends on such a futile exercise. Probably only about a fifth of those whose asylum applications have been rejected have been removed. The illegals will remain because deporting them is beyond the administrative capability of the authorities. One day those migrants will become citizens.

Even President Bush, not normally thought to be a political wimp, is allowing illegal entrants to stay. He pledged that they would have to pay a penalty for breaking the law, pay back taxes, learn English and “wait in line” behind the legal migrants. In weasel speak that means he is declaring an amnesty.

Our government has not been inactive or wholly ineffective. It has focused on processing new asylum applications more effectively. If would-be applicants see that their case will be dealt with quickly and there is some chance that they will be removed, they may try their luck elsewhere. Roberts was also right to say that the most efficient thing to do is to raid the premises of large-scale employers where you might catch a dozen illegals in one swoop.

For the future Blair puts his faith in so-called electronic borders and identity cards. But that is disingenuous. Are the police really going to ask us in the street to produce our papers? Will those who cannot prove their right to be here be marched off for deportation? I doubt it and even if it did happen the legal process in each case would remain cumbersome, the outcome uncertain.

I am no more convinced by the ideas put forward elsewhere in this newspaper by David Goodhart, the editor of Prospect magazine. He calls for a sharper distinction between entitlements for British citizens and for those who are merely migrants. It is hard to see that working. Are the children of foreigners to receive poorer education or lower quality healthcare or be expected to live on below subsistence incomes? Apart from the injustices that we are rightly too squeamish to tolerate, it seems a poor recipe for good community relations or law and order.

Nor could such a formula be applied to the hundreds of thousands of Poles and other central Europeans who, as citizens of the European Union, come here with equal rights.

The Blair government worked hard to expand the EU to include them. The British middle classes have welcomed the newcomers as cheap but industrious workers in their homes and restaurants. A survey of Polish migrants published last week revealed that they believe their “whiteness” to be an advantage in getting work here. British whites probably feel little anxiety about migrants who look European and come from a mainly Christian country, especially as many will go home once they have made some money.

Given that there is little to be done about illegal immigrants already here and nothing that can be done about those who have arrived from EU countries in fulfilment of the government’s policy, it is dispiriting that politicians cannot be as straightforward with us as the commendably direct Roberts.

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