Giving your staff as much leave as they want is not guaranteed to make you popular.

Richard Branson is a master of canny self-publicity and Virgin’s policy of unlimited holiday for staff won him another welter of flattering headlines. Now a law firm has got with the zeitgeist, introducing a similar policy for its own employees.

Ashton KCJ looks like a happy and highly productive firm and I commend its initiative. But I predict that taking flexible working to this extreme won’t catch on in the law, even where an employee’s output targets are easy to define (eg the billable hour).

The flaws with an unlimited holiday policy become glaringly apparent when you actually think about it. Here are a few.

First, an unlimited holiday policy is inherently nonsensical. In theory you could take every day off, which means you’d be on holiday from - what? It’s a non-policy policy.

Straight away, then, the onus is on the employee to gauge what might be acceptable to both their employer and close colleagues. Which is fine if the workplace is a paragon of trust and autonomy, where everyone respects and works around the deadlines and priorities of everyone else and hierarchies rarely intrude. Ashton KCJ gives every impression of being just such a place. But it is surely in a small minority.

Second, an employer’s intentions may be entirely noble, but unless senior management has the absolute trust and respect of staff they may be misinterpreted. An invitation to take unlimited holiday is, after all, an implicit invitation not to take holiday. Listen for the grumbles on the shop floor: ’Is the hated boss class playing a mind game to keep me chained to my desk?’ 

Third, are you going to track how much holiday each person takes? If you are, then your policy looks like a sham. If there is no limit then you have no logical right to ask questions - it’s entirely a matter for the individual. If you are not tracking it, then that’s a potential recipe for organisational atrophy - and you won’t be able to prove you are abiding by the statutory 28-day minimum in the Working Time Regulations.

So then you are forced to include caveats. Indeed, Branson has done so: unlimited holiday is only for ’when [Virgin staff] feel 100% comfortable that they and their team are up to date on every project, and that their absence will not in any way damage the business’. Which sounds perfectly fair, until you consider that in professional jobs there is always more you can do than you have already done.

There is always the risk, too, that some staff won’t even take their statutory entitlement if they feel the pressure to stay in work. And that brings us back to the suspicion some will inevitably harbour that this was the intention all along.