When Natasha Kaplinsky announced that she is expecting a baby, instead of sugary references to the imminent patter of tiny feet, she faced a vicious backlash. Her crime? At the time she was only six weeks into a job newsreading on channel Five. The implication is that by failing to tell her prospective employers about her plans for a family, she was somehow exploiting them and cheating the system. It's hard to believe it is 33 years since it became illegal to ask a woman at a job interview about her intentions regarding children.

Of course, that didn't stop Alan Sugar, Neanderthal par excellence, from grilling a contestant on The Apprentice about her childcare plans. He has since claimed that many employers simply bin the CVs of younger female job applicants to avoid the expense and hassle of handling maternity leave. This is more than bravado. A recent survey found that 68% of employers would like to regain the right to quiz women about family plans and a YouGov poll last year of 1000 UK directors found 19% avoided hiring all women of child-bearing age.

Here is a classic rock-versus-hard-place dilemma. Either we agree to such questions and see our job prospects shrivel if we even vaguely aspire to motherhood, or we stay mum, so to speak, and see our prospects undermined anyway. Then, around age 45, maternity discrimination in the jobs market eases gently into good old-fashioned ageism.

Four decades after sex equality legislation, it is amazing that this debate is still going on. Imagine the outrage if someone suggested that it is perfectly in order to bin job applications from anyone who is disabled or black or Irish? Yet not one government minister bothered to criticise Sugar.

It's not hard to see why this old chestnut has sprouted anew. Last year the right to maternity leave rose from six to nine months and will be extended to a year from December. Statutory Maternity Pay (of up to £117.18 a week) will be increased from 33 to 39 weeks. For those of us who were forced to abandon the cotside at 26 weeks, this is a cause for celebration.

My first day back after baby number one remains cruelly etched on the memory: the drive to the office, wiping away the tears at every set of traffic lights, followed by eight hours struggling to construct a feature about Star Wars - not the films but Ronald Reagan's dotty anti-nuclear brolly - as all the while a pair of increasingly hard and soggy cannonballs loomed before me. For several months, going to work felt like pulling my own teeth without anaesthetic.

But hallelujahs are apparently premature. This week Nicola Brewer, chief executive of the Equality and Human Rights Commission, bravely articulated what many others have been thinking: that the extension of maternity leave may sabotage women's career prospects. She describes this as "an inconvenient truth".

The problem is that giving these rights to mothers, while leaving fathers' entitlement at just two weeks' leave, means Britain now boasts the most unequal parental rights in Europe. The law effectively entrenches gender stereotyping of mothers as carers, even though many modern dads would love to spend more time getting to know their flesh and blood.

The situation and the best solution are well illustrated by my friend Diana. A Scots ophthalmologist married to a Norwegian, she surprised me when I raved about Norway's generous maternity provision 20 years ago. "The problem for us is that women likely to have families find it hard to get work," she said. Fortunately for her, there was a shortage of qualified eye doctors. Today in Norway, after the first few months, maternity leave gives way to parental leave, with either parent entitled to take more than a year off work. One of Diana's sons, a high-flying young finance director, took leave after the birth of both of his children, freeing his wife to return to her job as a GP. As a result he has an unusually close and delightful relationship with his son and daughter.

British contrasts are painful.

The government plans to allow women to transfer the second six months of maternity leave to their partners, but this is ill-conceived, according to Nicola Brewer and pressure groups such as the feminist Fawcett Society as well as the men's lobby group, Fathers Direct.

All favour gender-neutral parental leave. This would not produce a revolution overnight, mainly because in 80% of couples men earn more. And while mothers often make a conscious decision to compromise their career ambitions, initially at least, men would be reluctant to take time off for fear of harming their promotion prospects. But we need to start somewhere.

As Katherine Rake of the Fawcett Society points out, there is a centuries-old structural problem about the labour market: it was designed by men, for men. "We're trying to shoehorn women into it."

We don't always fit and our inconvenient habit of nipping off periodically to produce the next generation is apparently our most irritating habit. A news editor once asked me why women couldn't just choose between a career and motherhood. I asked him to pick between his job and his kids. That shut him up.

A colleague had become pregnant on virtually the same day as me purely by coincidence, though, of course, office gossip insisted it was some feminist plot. We duly arranged The Herald's first jobshare. We were lucky to have a strong union and a sympathetic editor. According to the Fawcett Society, at least 30,000 women annually continue to lose their jobs simply because they are pregnant and 45% of all pregnant women at work face discrimination or unfavourable treatment. This week 28-year old Gillian Devlin from Hamilton was awarded £10,000 after being forced to resign from her Home Office post.

When people wonder why 40 years after the Equal Pay Act, women in full-time work still earn on average 17% less than men, this is where to look. While fathers tend to climb steadily the professional and managerial ladder, mothers come in and out of the workplace, often going backwards in career terms and then being denied promotion for want of experience.

It is high time we recognised that a lack of flexibility in the British workplace disadvantages not only mothers but fathers too, robbed of family time by Britain's long hours culture. This rigidity means that an estimated 6.6 million people in Britain are not fully using their skills and experience. Allowing employees to have more say in where and when they work would also help those caring for ageing parents or disabled family members, the disabled themselves and those who would like to coast down towards retirement.

Meanwhile, the biggest source of discrimination in the workplace remains the possession of two X chromosomes.