If you want to prick the nation’s conscience only two words are necessary: working mothers. And Penelope Leach, the author and child psychologist often credited with inducing guilt in parents, has done it again.

Not that this is her intention. Her latest announcement — that children who are cared for by their mothers for the first three years do better in developmental tests than those looked after by nurseries, nannies, childminders or relatives — is based on a study of 1,200 children that began seven years ago. This is not a conclusion designed to take a swipe at mothers who farm out their children in order to work and pay the bills; it is clinical evidence, and this makes it all the more powerful to anyone who is insecure about his or her credibility as a parent. Which, of course, means all working mothers.

There has never been any doubting Leach’s credentials to advise on childcare, and to advise working mothers specifically, because she has always been one. In the late 1960s when she had her daughter, Melissa, she had graduated from Cambridge and gained her PhD, and she worked part-time until her second child, Matthew, was nearly two. Then he was hospitalised with meningitis, she took six weeks off work and soon discovered that her employers were “frankly bloody horrible ”. When she returned to work, leaving a howling baby who “mistrusted anybody but me”, she decided that full-time academic work was not for her.

When her parenting bible, Baby and Child, was published in 1977 her credo was clear enough: it was not Mummy who was in charge here, but the baby. The mother’s role was to fit in around the child, who would eat and sleep when he or she wanted. Motherhood was a 24-hour job, she declared bravely; children were not small animals to be tamed, but young human beings who needed to be talked to and treated with respect.

This contrasted with Dr Benjamin Spock, whose advice to be an instinctive parent had been taken literally by many 1950s mothers. His view was that parenting could be fun — a revolutionary idea for parents who knew only traditional roles — and children were blank slates on which parents could write.

That was not Leach’s view, and neither did her instincts square with the emerging feminism of the time. So it is unsurprising that when Leach revised her best-known book in 2003 (it became Your Baby and Child) she started all over again and wrote for mothers who she assumed would be working.

By this time Gina Ford, the former maternity nurse and bestselling author of The Contented Little Baby Book, was delighting working mothers by telling them that Mummy comes first, and that the way to make this work is for babies to have rigid routines. Mothers should not cuddle their babies when they felt like it, and babies should be left to cry. Leach responded by saying: “What if you don’t have that kind of baby?” and pointed out that instruction manuals for people don’t suit every individual. “The security of an infant’s attachment to mother and the sensitivity of her care go together,” she wrote.

It is doubtless significant that Leach, now 67 and a grandmother, was sometimes separated from her own parents as a child when she was an evacuee during the war. Her parents divorced when she was 12 and for a couple of years she was shuttled between them; during these journeys she had to care for her sister who was seven years younger. She had an uncomfortable relationship with her father, an authoritarian parent, but adored her mother, who was more relaxed: “She was not permissive exactly, just very devoted, interested, intelligent, warm.”

Leach is militantly in favour of mothers working if it suits them; what she is against is inflexible employers. In her perfect world both parents would be able to adapt their working patterns at different stages of their children’s lives.

Indeed she never set out to be dogmatic, and has surely fed the most important debate of our times with a fine blend of academic research, warmth and wisdom. Unconditional love, she has said, is the only thing that really matters.

'I don't have a trust fund. I go to work because I have to'
By Carol Midgley

So, another survey and another super-size dollop of guilt for working mothers, otherwise known as Selfish Career Women (SCW). The most in-depth study into childcare to date finds that young children looked after by stay-at-home mothers develop better than those cared for by nannies, childminders or grandparents, and those at group nurseries fare worst. This, I realise with a churning stomach, must make me an alpha SCW since my 20-month-old daughter has been in full-time nursery care since the age of six months.

Why did I opt for a nursery? Well, after weeks of sleepless nights, knowing we had no relatives living nearby who could step in, it seemed the best solution.

Unfairly I’m sure, I ruled out nannies because I was unable to dispel the image of a lonely and possibly resentful young girl stuck in the house all day with a child she couldn’t be bothered to play with. The idea of a childminder scared me because once she closed her front door there was no way of knowing what was going on (the recent story of a childminder writing “nigger” on the forehead of a little black girl in her care has not helped this paranoia). At least nurseries are open to scrutiny, I thought. There will be Ofsted certificates on the wall and health and safety checks. She will make toddler friends. So far, touch wood, the nursery I chose has been wonderful.