First British women came under attack for being chubbier and less chic than their stylish Gallic sisters. Now another critical salvo has been fired across the Channel, this time over our ability to bring up well-behaved children.
Forget the euro crisis. This latest attack in the entente discordiale strikes at the heart of parental angst and highlights a fundamental gulf in parenting philosophy between the British and French.
It also taps into the British self-flagellation previously aired in the 2004 dieting tome French Women Don't Get Fat.
In her book French Children Don't Throw Food, out this month, American mother-of-three Pamela Druckerman, who lives in Paris, asks how the French manage to raise children who, unlike many of their US or British counterparts, sleep through the night at two months, are not picky eaters, do not throw tantrums in the supermarket and go to bed without making a fuss, while their mothers "continue looking so cool and sexy".
"What British parent hasn't noticed, on visiting France, how well behaved French children are, compared to our own?" ask her publishers, suggesting that "with a notebook stashed in her diaper bag", Druckerman discovers the "secrets to raising a society of good little sleepers, gourmet eaters and reasonably relaxed parents".
That is a bundle of generalisations and stereotypes, but then few things are guaranteed to polarise opinions – and boost sales – as much as how we raise and educate our offspring.
Discipline versus encouragement, chastisement versus laissez-faire, a sharp shrill "ça suffit!" (that's enough!), versus the mollycoddling "now let's not do that, shall we?" reasoning of the so-called Anglo-Saxon – meaning British or American – mum. And above all, that essential Gallic parenting tool, la fessée, or smacked bottom, versus the British naughty step.
It is probably safe to assume that Druckerman's copious note-taking among "Parisian friends and neighbours" centred on a certain section of what would be described as middle-class families in English or aisé in French. Speaking to mothers who fit that description – as opposed to those struggling to raise families in France's gritty suburbs – the Observer discovered a general consensus that parents either side of the Channel have a radically different vision of their children and an equally contrasting way of raising them.
In France a child is rarely considered an equal, but a small human being ready to be formatted, partly by its parents but mostly by the state education system. It has to be encadré, kept within a clearly and often rigidly defined framework that places disciplines such as manners and mathematics above creativity and expression.
A French child who has a tantrum is unlikely to be cut any slack on the grounds that it is expressing itself, is quite likely to be smacked and, if the tantrums continue, packed off to see a child psychologist. The "terrible twos" is not a recognised phenomenon in France.
Lise Fuccellaro, mother of four children aged eight, 12, 14 and 16, lived in England for seven years before returning to the Paris region.
"What struck me in England was how extremely patient and gentle English mothers were with their children compared with French parents," she said.
"They would get upset much less often and never seem to have the great shouty crises we have. But at the table, French children are without doubt much better behaved. It's remarkable how British children just don't sit nicely and aren't taught any respect for people around them. It would be unthinkable to most French parents to inflict their children on other people."
Bénédicte Juston, 37, a French languages professor, who lives in west London with her three boys aged six, eight and 10, agrees: "British parents definitely have a different approach. They are much less likely to shout 'stop' at their children and more likely to be calm and ask, 'why did you do that?' We are more Latin… it's a case of 'stop that or you'll get a smack'.
"I often notice I am the only parent shouting at my child in the street."
In France, British expat parents are often dismayed at the stifling rigidity of French schools, in which learning by rote is more important than learning to reason, where creativity is strangled by conformity and where what a child has to say is less important than doing so with impeccable grammar and writing.
Friends in London admire our children's faultless script – they learn to use fountain pens in the first year of primary school – but are horrified when told that the neighbours' six-year-old was declared "nul" – useless – by his teacher and marked down, even when giving the correct answer, because their ornate, loopy, joined-up handwriting was not up to scratch.
"You couldn't do that over here. The parents would be up to the school complaining about the teacher in a flash," said one British friend.
Juston added: "The biggest difference in bringing up children in France and Britain are the schools. If, for example, a British child is artistic but not so good at maths, everyone says never mind, it will come. In France, the teacher will summon the parents and tell them: your child cannot write and cannot add up, we don't care about anything else.
"Whether they are happy, have friends or are kind is an added bonus in the way we educate our children."
Druckerman makes a great deal of how French children are taught to be better behaved in public and social situations. Passengers on the Eurostar can often identify a child's nationality without hearing them speak. You can more or less bet the one running up and down the carriage screaming his head off will not be French.
Bénédicte Lohe-Le Blanc, 38, a teacher originally from Brittany, and her husband Vincent, 39, live with their three children, Sten, 11, Yaelle, nine, and Kenan, six, in west London. She believes British parents are lax with their children.
"I was at an English friend's house and her six-year-old son was thumping the piano as we were trying to speak. His mother said 'yes that's lovely, but not so loud'. He just carried on. I said to myself if this was France the child would have been hauled off to another part of the room and made to stop. British parental culture is very relaxed, while we terrorise our children."
She is convinced this is a backlash from the laissez-faire attitudes that prevailed in France after the May 1968 student riots, that brought a form of the swinging 60s to French society.
"In the wake of May 68 we were more relaxed and we rejected authority. But my generation saw the damage that lack of limits did to children and how it ultimately caused them problems, so we went back to being authoritarian."
She added: "We consider our children to be small people, but they are not equal to an adult. They need authority, they need rules and they need to be kept in line. A child is a child and has his place. In France we see authority as a form of affection and believe that a child blossoms because of, not in spite of, that authority. The bottom line is my child can have his own opinion, but it's me who decides."
French mothers often have a greater sense of detachment from their children, says Dr Caroline Thompson, a Paris-based child psychologist and family therapist who grew up in America until the age of eight and has a British father. She believes differences in parenting are largely down to the difference in how the mothers view themselves.
"French women are often loth to leave the arena of womanhood and enter that of motherhood. They do not define themselves as mothers and don't want to be defined as such. For American and British women, motherhood has become such a big event in our lives. It's amazing that women's liberation has brought us to this extreme that motherhood is the coolest thing to do in your life.
"The place of a child in its mother's mind is much more defined and separate in France. An Anglo-Saxon mother faced with the piano-thumping child would be saying 'what is my child feeling?'. A French mother would be asking 'what am I feeling?'. If we empathise too much with our children that it becomes intolerable to punish or limit them, this is terrible for the child. If you believe your main objective is to be liked by your child, you are in big trouble."
"But we Anglo-Saxon mothers have created a backlash in which smart, accomplished women give up everything and their child becomes 'the project'. This in turn puts pressure on the child. Bringing up a child successfully is about enabling that child to leave you and go out into the world on their own."
Lise Fuccellaro believes British children may be less disciplined than their French cousins, but says they often grow up to be nicer adults: "French children may be better brought up in the strictest sense, but they grow up to be very individualistic," she said.
"British children are more open. They may be noisier and less well behaved, but they seem to become much more social and community-minded as adults."