To return to ID cards, the Register notes that the current immigration problems highlight the inevitable failure of ID cards.
Which leaves Blair's plans to solve the immigration question through the application of IT with difficulties on several levels. The border defences themselves will be expensive to keep up, will put non-immigrant travellers through annoying hoops, but will do little to impede would-be immigrants coming in under false pretences and/or false documentation. They will give the UK a biometric database of a reasonable percentage of the future defaulters, but these can only rationally be tracked down in-country via fairly repressive controls which again will impact heavily on the rest of the population. These measures will produce a large (and, assuming the supply is not shut off, continually growing) group of candidates for deportation, and as these will likely abscond if released, they must be detained until...
If we make things uncomfortable for immigrants, by denying new entrants welfare benefits, the Left will argue that they will turn to crime. It should be noted that immigrant criminals are drawing welfare benefits, often on an illegal basis, and that the absence of a welfare state is unlikely to prevent their lawbreaking.