To coincide with International Women's Day, Legal Week has asked a number of high profile female law firm leaders and partners for their advice for other women hoping for the same success. In this interview, Ruth Grant – global chair of Hogan Lovells' diversity and inclusion committee and former London managing partner – discusses role models, ambition and the path to partnership

Did you ever doubt whether becoming a partner was something you wanted to do? No. Honestly, there were not many alternatives in the 1980s for litigation lawyers. It was whether you became a partner where you were trained or whether you moved on to another firm and became a partner.

Who encouraged you to do it and helped you through the process? My 'sponsor' (in modern parlance) was John Trotter – a longstanding litigation partner who I worked for, and subsequently with, throughout my career until his retirement a few years ago. We still have Christmas lunch every year with our PAs as we always used to.

When did you first realise you wanted a firmwide leadership role and what early steps did you take to get there? Not practising what I now preach, I only realised when I was asked. It had not occurred to me that I might take on such a role but when I was asked I was thrilled at the prospect. I just said yes.

Why do you think there are so few women in management in law firms? It is in part a reflection of the lack of women partners of course and, perhaps, some women still adopting some of my own approach; it hadn't crossed my mind to look for such a role. That is changing and, in my firm, has changed. With leadership programmes and many more women in middle management – leading offices and practice areas – we have moved rapidly to 40% of practice group leaders and 40% of regional managing partners being women. That is bound to be the way things develop across law firms more generally.

How important do you think it is to have female role models at firms? Vital, but they have to be 'real' to the women lawyers coming through. Some very senior super performers, although great, are unlikely to be valid role models. A role model has to be someone whose life bears comparison with the associate in question.

And how important a role do men need to play in changing the imbalance? Men are vital too. Where they are in the majority in management and within a partnership, the senior men have to have the vision to see why more women would be good for business. That means good for client service, for recruitment and retention and, not least, because 50% of the best lawyers must be women.

Do you think there will ever be gender parity at both partner and law firm management level? Why? There is absolutely no reason why there should not be gender parity, especially in management, given most roles are appointments by existing management and just need to be made. At partner level, I hope there will be gender parity but for that to happen will require removing the unconscious biases in our systems that discourage a proportion of excellent women from staying with firms. I think it will also involve structural change and, for most firms, an adjustment in what they measure and assess through their partner promotion processes. It can't just be about numbers.

What are the most important things firms can do to increase the number of women becoming partners and then going on to become leaders? Tell good women that they can and should be partners, train line partners in how to manage their diverse talent well and hold them to account for that, recognising those that do it well. Don't assume the best will float to the top. There are too many elements in the working environment that together create a system that is biased against women (and others who are not from the majority background and culture in organisations). Most good leaders are not just made that way, they develop that way: give women opportunities to lead and provide leadership development training.

Do you think working in a City law firm can be compatible with men or women wanting to build a career as a partner and taking time out/on reduced hours to be with their family or for other work/life balance reasons? Yes. We already see a variety of models in transactional practices. Hogan Lovells has a global agile working policy in place that facilitates partners and associates who work annualised hours for example, who work nine months of the year, who take extended leave over the summer and such like. And that's with our current methods of work.

The real way to solve the problem is to address team structure. There are very few matters that City firms work on that don't have teams that share the work. It is harder to structure a team to take account of people who can't work 24/7 but it can and should be done. The issue that does not get discussed, but which is at the root of the problem, is the cost of allowing for flexibility. Clients won't pay for that and to date, firms have not directly had to pay for it by having cadres of associates willing to work 24/7.

What are your top three tips for female lawyers looking to become partners? Tell the powers that be that you want to be a partner, make sure you know what is expected of you to be a partner (what success looks like changes as lawyers become more senior – make sure you know what it is), find those who are prepared to and able to help your career and commit to them as well as asking them to commit to you.

And for female partners looking for a firmwide management post? Again, say what you want. Look for opportunities to take on more junior leadership roles – but be careful, don't get stereotyped. Get external-facing or firmwide roles that expose you to the firm's decision makers. And find your sponsor.

Why is it important that women go for such roles and what are the best bits of doing them? If you have a management role, you have influence – you can help shape the firm and its culture. Most people relish that. With critical mass – 30% minimum – you cease to feel like a lone voice or feel you have to play the male game; you stop missing out on the key discussions taking place in the gents.

Do you have any regrets about becoming a partner/taking on a leadership role? I have no real regrets. It has shaped who I am. I feel proud of where I have come from and what I have achieved. I feel pleased for my daughter, who knows that she can achieve anything she wants and is as good as the next person. That said, I wish I had more time for friends, to have hobbies and to read for pleasure, but everything in life has an element of compromise.

Do you think there will ever be a female leader of a magic circle law firm? When/why? Of course there will. It is just a matter of the right person wanting it and having had the opportunities to build their experience. There is nothing magic about the so-called magic circle in that regard. And when? It's more than 25 years since Lesley MacDonagh first led Hogan Lovells. It can't be too long for the same to happen in every other large law firm.