Some people are lucky with their timing and their friends. Paul Dacre is one of them. This week the editor of the Daily Mail gave a lively lecture berating the judges and extolling the tabloid press, of which he is such a luminary. Rightly, and not entirely surprisingly, his words received lots of media airtime and coverage.

Twenty-four hours later, however, an independent survey revealed something entirely at odds with Dacre's views. The survey found that eight times more British people trust judges to tell the truth than trust tabloid journalists to do so. Sadly, but not at all surprisingly, this finding went almost wholly unreported. Lucky, privileged Dacre.

I say this finding went unreported, which it did. However, other parts of the research from which it came - a survey of attitudes towards conduct in public life commissioned by the independent committee on standards - were vigorously covered. One part of the report in particular caught the media eye. Many papers carried stories about the low esteem in which the public holds government ministers and MPs - "Get your snouts out of the trough" (Daily Mail), "Trust in MPs at new low" (the Sun), "Sleaze tsar slams greedy MPs" (the Mirror). There was nothing in any of these reports, however, about public attitudes to the media.

So let me correct the tabloids' omission. The survey asked the public how much they trusted 17 different professions to tell the truth. Top of the list as usual were family doctors, trusted by 94% of the public, followed by headteachers (83%) and judges (82%). Ministers and MPs indeed trailed far behind, trusted by 27% and 26% respectively - as the red-tops were quick to point out. At the very back of the line, though, came another group, tabloid journalists, who were trusted to tell the truth by a miserable 10% of the population. Yet this particular finding has not been published in any newspaper until now.

Even this, though, only scratches the surface of what this striking survey revealed about public attitudes to the media in general and to the tabloids in particular. Tabloid readers, the survey found, are more likely than the readers of broadsheet papers or of no newspapers at all to believe that standards of conduct in public life are low, are getting worse, and to think that the relevant authorities are not upholding the right rules. Given their exposure to the sort of stories quoted above, perhaps this is not exactly surprising.

What may surprise, though, is the scepticism of readers towards tabloids. The survey asked their opinion of the papers. Do they "do a good job of keeping politicians accountable?" Yes, said 43%. What about "help the public to learn about what is happening in politics?" Not so sure. This time only 31% of readers thought they did.

Then the figures become really dire. "Generally fair in their representation of politicians?" Only 13% thought that applied to the tabloids. "Look for any excuse to tarnish the name of politicians?" A massive 90% agreed with that one. "Focus on negative stories about politics and politicians?" Almost the same, 87%. And finally, "more interested in getting a story than telling the truth?" This time an overwhelming 82% of tabloid readers concurred.

You might suppose that the tabloids would find these devastating figures - casting their papers as unfair, negative and untruthful in the eyes of their own readers, not of some liberal columnist - somewhat chastening. And certainly some of them will be chastened. But there's also a bit of the tabloid DNA that is hardwired never to be self-critical when challenged and that simply rolls with the punches at such moments. What readers want more than anything, the hacks tend to say, is entertainment. The readers know perfectly well that the stories aren't always fair, positive or true - and so do we - but the readers know, and we the journalists know too, that in the end they don't take any of it too seriously. "Dull doesn't sell newspapers," as Dacre put it this week. "Boring doesn't pay the mortgage."

Or maybe true doesn't pay it either? In the end Dacre is adopting what is essentially the Russell Brand defence. This says that the liberty to behave immorally will always trump the responsibility to behave morally because that's the way people are. Put sex and Obama in the headline and you will get the hits and the sales, even if there isn't a sex and Obama story. It echoes something that the Mail's Melanie Phillips used to say, back in her Guardian days, that any fool can put up the circulation.

Yet this is not the code that the tabloids say they live by. Ultimately, they do not defend themselves to the public on the basis of the right to be foolish, untrue or rude, or even to sell newspapers. They defend themselves, as Dacre did again this week, by asserting their civic virtue. "Our extensive coverage of public affairs is the glue of democracy," he told his audience. At this, it is hard to know whether to laugh or cry. Glue of democracy? Laxative more likely.

Only connect, urged Dacre, quoting EM Forster. If only we did. Too few make the connection between the way something like this week's public attitudes survey is so wilfully misrepresented, and the perception among tabloid readers that standards of public life are in headlong systemic decline.

In reality, as even Dacre himself said in his lecture, ours is not a particularly corrupt society. Sir Christopher Kelly of the standards committee naturally says the same thing. No one who knows our public life seriously believes otherwise, save in the occasional case at the margins. Yet increasingly the public believes the worst about ministers and MPs. They do so not because it is true, but because that is the message that many of them hear most of the time.

There is not a lot that can be done in a hurry about the tabloids or their readers. But at least acknowledge the problem and determine not to make it worse. Tabloid readers, says the survey, are less likely than others to seek out other sources of news and information about politics. Only 4% of them go to a political website in a typical week. The upshot is a civic Catch-22 in which tabloid readers get large amounts of their political information from newspapers which they overwhelmingly believe are unfair and which neither they nor anyone else trusts in any significant numbers to tell the truth. It is often said that a society gets the press it deserves, but it is also true that the press gets the society it deserves.

martin.kettle@theguardian.com