Columnist and Radio 4 presenter Libby Purves was the bearer of bad news this week for people who like to keep cushy job options 'in the family'. Writing in The Times she announced - which was news to me - that the practice is now a no-no at the Beeb. "If your child, nephew, friend or sister-in-law wants work experience (even unpaid) at the BBC these days . . . there is no way an insider can fix it."

Immediately, a thought crossed my mind: does she know this because she has tried? Unworthy as this suspicion might seem, there could be justification for it. Does Ms Purves not have form in this area? There are those of us who recall a number of bulletins from Oxford and other articles penned in The Times by a certain Rose Heiney. There must have been many student contemporaries intrigued to see how easy it seemed to be for Rose to get her undergraduate musings into the Thunderer - but then she is the daughter of one of its star contributors.

Nepotism in newspapers is one of the few aspects of the modern press not covered in Nick Davies's admirable (and disturbing) new book Flat Earth News (Chatto & Windus, £17.99). The index passes without interruption from "neocons" (we all know about those) to "neutrality". On the latter subject, Davies has most interesting things to say. This supposed virtue, he argues, has become an important device for the spreaders of disinformation and the "churnalists" (I'm sure everyone can divine Davies's meaning) that help in their task. He writes: "Balanced reporting was a brave and necessary step for honest journalists to declare that they would show no favour, that they would be willing to tell the truth from all sides. Now, however, that context has changed, and the demand for balance has become a gateway through which spokesmen for the consensus are invited to enter our stories with their comments, regardless of whether or not they are false, distorted or propaganda. The honourable convention aimed at unearthing the facts has become a coward's compromise aimed at dispatching quick copy with which nobody will quarrel."

The valiant-for-truth writers and broadcasters whom I most admire have united in applauding Davies's work. You can see above what John Humphrys says. It would give a spectacular boost to sales if the newspaper-reading public responded in the way he advises. Private Eye editor Ian Hislop also calls it "a must-read", and the Eye very commendably printed a goodly chunk of it to assist in this process. Shamefully (but understandably) the book was largely ignored by the national newspapers it attacks.

The Oxford Times makes an appearance in its pages - but not, I hasten to add, in any way detrimental to its glowing reputation, unless it be that any of my colleagues takes exception to the idea that he or she is unable to digest complicated facts, if hard-working. What Davies explains concerns misrepresentation of figures about global warming - that it is not nearly as bad as the doommongers pretend. A press release had been issued misrepresenting the findings of, turning a predicted 3C rise in temperature into 10C and even 11C. Its principal investigator, Dr Myles Allen, explained: "Our press advisors tell us . . . to make sure that the press release could be used by the hard-working journalist on the Oxford Times who doesn't have the time to go and read the whole story, so they can essentially copy it out."

I am glad to say that Davies adds: "It was not just the local reporter on the Oxford Times who didn't have time to go and read the whole report. On the basis of the stories they published, it seems that none of the national journalists who covered the report actually read it: they relied upon the press release and never once mentioned the majority prediction of a 3C rise. The process as a whole simply shunted the truth into the sidings."

If this story is instructive, no less so is what Davies has to say about the so-called Nat West Three. In the month that slimy trio Giles Darby, David Bermingham and Gary Mulgrew paid the price for their crimes - 37 months each in stir - it is astonishing to learn of the public relations manipulation that led to them being thought heroes. Of course it never fooled me, but then of course I don't write for the national press.