However, David Blunkett will hope that Levelling Down is read by all those Labour activists who fear he is losing faith in comprehensive education. Its charge against him is that he is assiduously implementing party policy.
Writing as if he has decoded a secret message, Williams reveals that clause 4 of the Bill "puts a blanket ban on selective admissions in all schools except for permitted forms". Perhaps he was out of the country during May 1997, or maybe he did not read Blunkett's lips when the famous promise was made.
Tessa Keswick, the improbable director of the CPS, should have told him that the comprehensive school party won the election by a landslide. That does not mean that the Government's policies are beyond criticism, but they have to be challenged on their merits. All Williams does is assert they are wrong. Nothing in the pamphlet encourages faith in his judgment.
Even its opening sentence is an historical error. "By the mid-1980s the extent of schools' underperformance was becoming apparent." Some of us recall Jim Callaghan's Ruskin speech in 1976. It was the public manifestation of a series of questions that the new Prime Minister had sent to his Secretary of State for Education: "Is she satisfied with the basic teaching of the three Rs? Is the curriculum sufficiently relevant and penetrating for older children in comprehensive schools?" For good or ill, it began all the soul-searching about "standards" that has ended with league tables, naming and shaming and beacon schools.
Perhaps it was just bad luck that the complaints in Levelling Down about the death of diversity were published during the week in which details of the education action zones were announced. But Williams must have known that the Government was establishing more specialist schools - and that every comprehensive school that developed a "speciality" would be allowed to choose 10 per cent of its intake from pupils who wished to study that subject.
In truth, Williams wants only one sort of diversity: a small number of superior schools amongst the lumpen mass, and the right of the most self-confident parents to talk their children into them.
The serious part of the pamphlet is Chapter 5, "The impact of the Bill on an excellent school". The school in question is the London Oratory, chosen, I suspect, partly because the Prime Minister sends his sons there and partly because the headmaster disagrees with Government policy. The London Oratory, Williams write?s, "will no longer be in full control of the Roman Catholic nature of its intake".
That is simply untrue, as the Prime Minister patiently explained in the House of Commons last week. Interviews, to determine the religious affiliation of entrants to denominational schools, will still be allowed. The interesting question - for Blair as well as for Williams - is whether denominational schools can still hold general pre-entrance interviews. Do you have a room of your own in which you can do your homework? Where do you go on holiday?
Such questions determine class and status. Is this why, according to Professor Geoff Whitty of the Institute of Education, only 6 per cent of the London Oratory's pupils qualify for free school meals, whereas 40 per cent qualify in the local authority area as a whole? It may be that Irish Catholics in west London are more prosperous than other locals, but I doubt it. The London Oratory in effect selects the middle classes for special treatment. Unless the Prime Minister shares that view, he needs to make sure that denominational school interviews concern God, not Mammon.