But while the issue affects lawyers across the board, it is a particular problem balancing reduced hours with high-pressure transactional work.

Ask City partners for concrete examples of how flexible working arrangements are being used successfully and their response is positive - everyone can name the employment, pensions and tax lawyers, of all levels, doing just that.

But ask for tangible examples of it being used within M&A and banking teams and the response is entirely different.

The issue divides M&A partners. Few would deny that corporate associates and partners should be entitled to some flexibility but many are unconvinced client-facing lawyers can work part-time. As one partner at a US firm says: "You could not be a lead M&A partner and work flexi-time. You cannot say to your client in the middle of a deal: 'It will have to wait - I don't work Fridays'."

Even the more optimistic currently struggle to suggest how it would work in practice, and concrete examples of people actually doing it are even harder to find.

Ironically, the option many M&A partners think would be workable for associates is one that Simmons has just dropped from its revised flexible working scheme - working on a project-by-project basis.

As Simmons discovered, while it would allow the lawyer in question to work intensely on one or several transactions before taking extended time off, it proved unpopular with staff. True, it may help the 'Generation Y' types who still want the time to travel the world but for anyone with family or financial commitments it would not work, making it particularly unhelpful for those most likely to want flexible working - parents.

All of which leaves firms back at Simmons' revised position - a system that makes it easier for people to reduce time spent in the office, on the basis they will work additional hours at home or work part-time, preferably with the ability to be flexible about which days are spent at home.

It is hardly radical and, crucially, it still means anyone doing so has to be willing and able to work in the evenings. In fact, to stand a chance of getting any interesting client work they would have to be flexible about when they are available, the clients would have to be understanding and the rest of the practice would have to offer support to take over during the hours or days away from the office. The reality is that lawyers opting for this would see their client exposure reduced and the work they do changed to take account of the fact they cannot put in the overtime.

This may go some way towards pacifying those lawyers who genuinely want work-life balance as their main priority and are willing to sacrifice their career prospects to attain this. But, with current mindsets, the likelihood is that it would be of no use for someone who still sees partnership as their ultimate goal.

It may well just be the case that firms simply haven't tried that hard to find the ideal solution yet because, until now, they have not had to, but it remains the case that for every partner who claims 'it's better to have three-quarters of a quality act than none of it' there are three who are convinced it is 'just not consistent with the partnership track'.

Simmons & Simmons

But while the issue affects lawyers across the board, it is a particular problem balancing reduced hours with high-pressure transactional work.

Ask City partners for concrete examples of how flexible working arrangements are being used successfully and their response is positive - everyone can name the employment, pensions and tax lawyers, of all levels, doing just that.

But ask for tangible examples of it being used within M&A and banking teams and the response is entirely different.

The issue divides M&A partners. Few would deny that corporate associates and partners should be entitled to some flexibility but many are unconvinced client-facing lawyers can work part-time. As one partner at a US firm says: "You could not be a lead M&A partner and work flexi-time. You cannot say to your client in the middle of a deal: 'It will have to wait - I don't work Fridays'."

Even the more optimistic currently struggle to suggest how it would work in practice, and concrete examples of people actually doing it are even harder to find.

Ironically, the option many M&A partners think would be workable for associates is one that Simmons has just dropped from its revised flexible working scheme - working on a project-by-project basis.

As Simmons discovered, while it would allow the lawyer in question to work intensely on one or several transactions before taking extended time off, it proved unpopular with staff. True, it may help the 'Generation Y' types who still want the time to travel the world but for anyone with family or financial commitments it would not work, making it particularly unhelpful for those most likely to want flexible working - parents.

All of which leaves firms back at Simmons' revised position - a system that makes it easier for people to reduce time spent in the office, on the basis they will work additional hours at home or work part-time, preferably with the ability to be flexible about which days are spent at home.

It is hardly radical and, crucially, it still means anyone doing so has to be willing and able to work in the evenings. In fact, to stand a chance of getting any interesting client work they would have to be flexible about when they are available, the clients would have to be understanding and the rest of the practice would have to offer support to take over during the hours or days away from the office. The reality is that lawyers opting for this would see their client exposure reduced and the work they do changed to take account of the fact they cannot put in the overtime.

This may go some way towards pacifying those lawyers who genuinely want work-life balance as their main priority and are willing to sacrifice their career prospects to attain this. But, with current mindsets, the likelihood is that it would be of no use for someone who still sees partnership as their ultimate goal.

It may well just be the case that firms simply haven't tried that hard to find the ideal solution yet because, until now, they have not had to, but it remains the case that for every partner who claims 'it's better to have three-quarters of a quality act than none of it' there are three who are convinced it is 'just not consistent with the partnership track'.