It's been a very long time since UK law firms were viewed as cosy partnerships offering jobs for life on lockstep remuneration structures allowing earnings to go up in line with partners' ages. Some brutal partnership culls and lean times financially mean it's little surprise that partnership, and the long hours and high-pressure culture that goes alongside it, has lost its lustre for younger lawyers.

On average only 10% of partners across the firms are aged 56 or over, with this figure rising to 27% for those aged 51-plus and dropping to just 2% for over 60s. A handful of exceptions aside, the odds of still being a partner at 65 are slim to none.

Which, given the average life expectancy in the UK is now just shy of 80, means – irrespective of what retirement legislation actually says – partners have got a pretty long time to brush up their golf skills or cultivate that vineyard in the south of France. Too long.

The view may once have been that, as long as you keep only one wife and don't have too much of a penchant for fast cars, boats or multiple houses, then you can afford to comfortably retire at 50 or perhaps 55. This is going to become less true over time.

Particularly as our research shows it is not just the top-paying magic circle firms that are nudging those beginning to go grey towards the door. The firms with the lowest percentage of partners aged 51 or over are not in the magic circle at all, with Herbert Smith Freehills and DLA Piper holding that joint badge of honour and Eversheds not far behind. Indeed the firms with the highest percentage of partners aged 51-plus are Clifford Chance and Freshfields Bruckhaus Deringer.

All of which suggests that the tougher economic climate of recent years means partnerships are just as likely to be actively managed in firms that are not perceived as being particularly ruthless as in those that are.

While it's likely that in the coming years there will be growing recognition that some will want to work for longer, there's a limit to how far firms can go while still allowing young blood to join.

In short, partners need to be thinking very seriously about second career options or moves to US firms with softer stances on age long before someone taps them on the shoulder.