This week, Cameron gave a speech on economic policy in which he claimed the charity's posters were fostering a "cultural hostility to capitalism" and helping to turn "profit" and "free trade" into dirty words.
Christian Aid promptly hit the roof, condemning Cameron's comments - part of a speech that was supposed to prove he can grasp weighty topics - as an "ill-advised gibe", and saying that he'd completely missed the point of its Trade Justice campaign.
But that is only the start of it. For yesterday, Christian Aid discovered, on Cameron's personal internet site, a photograph, above, of their supposed critic actively endorsing Trade Justice.
More pressingly, it was also printed on his campaign leaflets at the general election without the charity's permission and, they claim, in breach of their photographer's copyright.
At best, this leaves him open to charges of hypocrisy, or worse. The Cameron camp, however, said yesterday that he'd only meant to criticise a particular poster and not the actual Trade Justice campaign.
Christian Aid still takes a dim view: "We've written to Cameron asking for a meeting, but he hasn't responded. As Christians, we are forgiving, but he was talking codswallop, and being a hypocrite too."
* Despite a vigorous campaign, the outspoken model Jasmine Lennard has failed to become the next Bond girl.
In a break from tradition, the producers of Casino Royale, who last month cast Daniel Craig in the title role, have ditched her in favour of somebody with a proven acting pedigree.
Lennard is still being considered for a couple of minor walk-on parts, but I understand that the casting agents are upset that details of her potential involvement were leaked to the press last month.
She further burned bridges at the launch of the TV show Football Italia on Wednesday, when asked for her views on the appointment of Craig.
"I like Daniel Craig's ruggedness, but I don't think he'll be a decent James Bond," she said. "He's not clean-cut enough and, please, James Bond as a blond? I'm afraid it just won't work."
Regardless of the setback, Lennard retains an impressive pedigree. Her mother, Marilyn Galsworthy, seduced Roger Moore in The Spy Who Loved Me.
* Sir Bob Geldof has, for some time, been the scruffiest man in showbusiness. But the current vogue for "grunge" is providing stiff competition for his crown.
The Irish TV station RTE arranged to interview Saint Bob, top, at the Groucho Club in London last week, and posted a researcher at the door to welcome him.
"Geldof was a bit late, and we were starting to wonder if he'd turn up at all, when in marched a slightly dishevelled man with a few days' worth of stubble," reports a cameraman.
"Our researcher extended her hand, and said: 'Hello, Mr Geldof, the interview is upstairs.' Unfortunately, the chap replied angrily: 'I'm Neil Morrissey, now why don't you get out of the way and let me go for some lunch?'"
* For an amiable man, Jim Naughtie was unusually cantankerous on yesterday's Today programme.
Twice, the elegant Scotsman squabbled with John Humphrys over the quality of links he'd ad-libbed between news items.
Perhaps he was suffering. For just four hours before he'd been due to arrive in the studio, Pandora had packed Naughtie into a taxi, following a convivial evening at the Cartoon Art Trust's annual awards.
To the amusement of passers-by, we hugged, before discussing potential hangovers.
"Please don't ask how I'll cope," he said, grabbing my shoulder for balance. "Just don't. I'll just have to go to bed again straight after I come off air."
I hope he's now recovered.
* On Wednesday, there was not one rebellion but two by Labour MPs in the Palace of Westminster.
That evening, a well-refreshed parliamentarian decided to force open the door linking the Strangers' Bar with the Commons Terrace. This has been locked in recent months, for "security reasons".
Tom Watson MP, a Labour whip, had his collar felt by security on suspicion of the crime. He was later questioned by a police officer before being released without charge.
"It was hot and busy, and there was a football match on television, so some of us wanted fresh air," explained Mr Watson yesterday.
"The door was already open when I got there. I wasn't actually arrested. I was just part of a little group trying to explain what had happened."
It was an eventful day for Mr Watson. Earlier, he'd been forced to break up a fist-fight between two colleagues - Bob Marshall-Andrews and Jim Dowd.Reuse content