Last month marked 793 years since Magna Carta was signed, a great step forward for the cause of liberty in Britain. Yet although there has been much progress over these eight centuries, there is one area of shame for lawyers like myself — that opportunities for high-flying women in our profession seem more suited to the 13th than the 21st century.

Legal practices must commit themselves to retaining and promoting the brightest and best female lawyers rather than accept that women will get to a certain age, take a career break and never return to work — or return in a reduced capacity.

It is not just a question of employment rights — it is also about the credibility of the profession. If law firms are to win the war for talent, they must ensure that their colleagues are well supported when trying to balance work and family commitments, and they need to find ways of making flexible working arrangements work for women as well as men.

Women’s prevalence in the legal profession is increasing — 60 per cent of last year’s intake of solicitors were women, compared with 52.2 per cent a decade ago — yet women are not progressing up the career ladder. Only 22 per cent of women solicitors are partners and these figures have shown no signs of improvement in the past ten years, despite hand-wringing, directives and promises of change. These figures are unacceptable.

The Government recently set out plans to increase diversity in the workplace that will help Britain to compete in the global economy, and the law industry needs to do the same — the wider UK financial services sector, which I represent, is successful because it aims to provide opportunities for all, based on merit, not gender.

Having worked as a corporate lawyer in the City for four decades I have experienced first hand the demands that a career as a partner in a top solicitors firm can put on one’s time and personal life. It is not easy juggling client needs with school sports days and nor should it be — being the best at something requires sacrifices and difficult choices. In reality it is often women who are forced to make these choices and more often than not these women are choosing family commitments over their career because the two are regarded as mutually exclusive.

This need not be the case — we live in a world of BlackBerrys, laptops, mobile phones and videoconferencing — a lawyer working for a top firm can respond to client needs whether he or she is located in Hampstead, Clapham or EC2. Thanks to this 21st-century-technology, the culture of presentee-ism can be reassessed. A career in the law does not need to be incompatible with other commitments, but law firms need to create incentives for productivity — men and women should be rewarded for quality of input rather than simply hours spent at a desk.

Part of the challenge is encouraging those who have taken career breaks to return to the profession. Having spent thousands of pounds training and developing young lawyers, losing them when they are reaching the pinnacle of their earning power makes no economic sense.

Those who are considering returning to work need to be reassured that their skills are still in demand and their needs will be accommodated. Often women are reluctant to return to work in the law because of concerns, real or otherwise, that combining family commitments and career is untenable.

We suffer from a culture that devalues part-time or flexible working. Women fear that they will be seen as demanding “special treatment” if they apply for flexible working hours or that doing so is tantamount to career suicide. Tackling this issue requires a change in people’s attitudes and men as well as women should be supported if they make such requests. In a typical career spanning 40 years, families and children will occupy only part of that. It is wrong to label people as no-hopers for partnership or put their career into the sidings because they need to take a backseat for a relatively short period of time. (I assume we all agree on the wider social point that a society without childcare is a society in which we are short-selling our collective future.)

It is 85 years since the first female, Carrie Morrison, qualified as a solicitor, and since then, as in other professions, women have made huge strides in the legal profession, but if we are to have more female managing partners, law lords and even lord mayors, we need to encourage women to stay in work and ensure women do not leave the profession at the very age they would be seeking partnership and promotion up the ranks.

The author is the Lord Mayor of London

Times Recommends

• Judges give up wigs in a case of modernisation
• ‘Paraffin mafia’ comes unstuck after €676m fines
• Total 'is ducking blame for fuel blast'