There is no shame in admitting that raising children may not come naturally.

Mary Poppins knew better than anyone that raising children is not always intuitive and is almost never easy. Since her contribution to the parenting debate it has become a truism that while a licence is required to drive a car, none is needed to have children.

David Cameron is one of those who finds this baffling. Since becoming prime minister he has twice championed the idea of parenting classes for everyone, not just those most likely to fail their children without outside help. Some decry this as a gratuitous extension of the nanny state. It is in fact a sound idea.

A report by the Mental Health Foundation notes that most mental health problems emerge early in life and family relationships are “pre- eminent” as a determinant of children’s future wellbeing. When these relationships are abusive or poisoned by drug or alcohol abuse, mechanisms already exist for social services to intervene. When they are merely failing to nurture a child, or support a teenager, less drastic interventions still make sense. Prevention always beats more costly treatment, and parenting classes fit that bill. The trouble is that every attempt so far to make them perceived as normal in the public mind has failed. “Aspirational” parenting classes, to use Mr Cameron’s preferred term, are even further off. New parents are reluctant to be told how to do something they assume should come naturally. More experienced parents may feel that a stigma attaches to taught parenting even if they have a child who would clearly benefit from it. That has to change. Parenting may have come naturally to our forebears on the savannah but the world in 2016 is a more complicated place.

Three quarters of all mental health problems emerge by the age of 20 and one in ten children leave school emotionally or mentally troubled in some way. Even without clinically diagnosed illness or a “chaotic” family life, teenagers can be a handful. As John Ashton, president of the Faculty of Public Health, tells The Times today, “there’s some terrible parenting among wealthy people . . . Everybody would benefit from some support.”

It has been assumed by ministers and public health officials in favour of parenting classes that the more widely they were offered the less stigma would attach to them. So far the evidence does not bear this out. When classes were first widely offered, by the coalition government in 2011, only 2 per cent of eligible parents took advantage of them and the scheme was dropped. A Glasgow project aimed at troubled families registered a 60 per cent dropout rate.

In January Mr Cameron earmarked £70 million for counselling sessions for 300,000 families at risk of breaking up, and floated the idea of vouchers for parenting classes.

It is time to move beyond ideas and confront the understandable problem of parental resistance to being told what to do. Model projects exist, albeit on a small scale. The Dundee Families Project has achieved remarkable results for parents coping with serious behavioural problems. Workshops run by the Parent Gym have given parents from all walks of life the relief of knowing that they are not struggling alone. Such schemes are often a vital first step towards timely clinical treatment that can prevent a lifetime of mental health problems. Miss Poppins might not have put it quite like that, but she would surely have approved.