The practice is almost exclusively couched in terms of the benefits to working mothers. Why shouldn’t men also want to leave the office at 5pm?

In the Akira Kurosawa film Ikuru, about a workaholic bureaucratic and his final quest for meaning, one of the characters recites the following joke:

‘You’ve never had a day off, have you?'

‘No.'

‘Why? Are you indispensable?'

‘No. I don’t want them to find out they can do without me.'

For me this witticism cuts to the heart of the problem of presenteeism in many offices – but it also says something about what is fast becoming an out-dated working practice.

Having a job isn’t about being at work, it’s about doing work. We can all get in early in the morning and log onto Facebook. But ultimately it’s output that counts.

So I’m often bemused by the way flexible working is almost exclusively couched in terms of the benefits to working mothers. Of course it can help them significantly, and the paucity of policies is a huge barrier to many, but that’s only part of the picture.

Why shouldn’t men also want to leave the office at 5pm, spend some time with their family, and log back online in the evening to finish outstanding work?

The point is flexible working isn’t about doing less – it’s about working smarter. In fact there’s an argument it can lead to increased productivity. Under the law of diminishing returns putting in regular 12-hour stints can’t be the most efficient way of doing things.

I’d also argue that way of working is damaging to all – not least firms’ profits. Every day a high-profile male City worker seems to get signed off due to exhaustion and stress. 

South-east firm McMillan Williams recently came top for the number of female partners in the Diversity League Table report, with just under half women.

Nicola Manning, partner at the firm, says a flexible working culture benefits everyone. The firm’s practice of letting partners have one day off per week to manage childcare and the attitude that it’s OK to have time off to look after sick children was not a formal policy decision. Rather it was a choice to respond to the needs of partners and associates as a modern employer would, she says.

The world has changed dramatically in the last 20 years, although some firms don’t seem to have noticed, with their long-hours, Gordon Gekko-style culture still prevalent. Looking at how they operate you’d think we were stuck in the power-suited 1980s when the world wide web was still a twinkle in Tim Berners-Lee’s eye.

 Kathleen Hall is a Gazette reporter