In the employment world, some legislative ideas just don’t work. Some have promise initially but don’t survive their first encounter with the real world – take a look at 2001’s Dignity at Work Bill, for example, to all outward appearances a brilliant spoof of a real piece of legislation but clearly written by someone with no actual experience of the workplace whatsoever. Other ideas make it into law but are by common and unspoken consent then broadly ignored, like employee shareholder status and (for those of a certain vintage) the Statutory Grievance and Disciplinary Procedures, both introduced to great fanfare and repealed in embarrassment and confusion very shortly afterwards. On the other hand, some ideas are so clearly and irretrievably doomed from the very moment of their conception that they do not deserve to see the light of day at all.

And so a big hand, please, for the TUC’s proposal to introduce legislation to outlaw workplace discrimination on the grounds of class in the same way as for race, gender, disability, etc. In societal ambition terms, unimpeachable, but as a piece of law, surely unworkable.

The thing about race, gender, disability, etc. is that broadly-speaking you know what you are looking at and the options are relatively limited. Age discrimination contains more shades of grey but ultimately someone’s age is a fact and ascertainable as such. You are either pregnant or not, married or not, transgender or not.

But class? How would you even begin to define it? By reference to the holidays you take, the car you drive, your accent, schools, clothes, tastes, parents, education, speech, newspaper, income, or an overweening air of either chippy resentment or louche entitlement?

In addition, race, sex, etc. are all absolutes, while class is clearly relative to one’s own stand-point, self-image and aspiration. To some people, everyone else is part of the one percent, while some others will see all their candidates and colleagues as just frightful common little oiks whose parents should have sent them to better schools if they wanted to be taken seriously, yah?

It goes without saying that unless you can define class or class strata precisely, any attempt to legislate about it credibly, let alone enforceably, is going to fail. However, at this stage the TUC says on BBC News online that it wishes to focus on tackling class inequality rather than to “ignite a lengthy debate about definitions“.

But you can’t have law without definitions. You can’t put the burden on an employer to show why it offered X the job and not Y if you cannot then separate X and Y on some objective legal basis apparent also to the employer. Particularly if it follows the disability regime to the extent of requiring employers to make reasonable adjustments to help alleviate any workplace disadvantage implicit in one’s class status, any piece of law more likely to reinforce the adoption of clunky class stereotypes is impossible to imagine.

Even once you have those definitions, who decides who falls into which? Is it an issue of perception by the would-be employer, or would we need an extension to the EHRC Equal Ops monitoring form? And who says that that form will be completed accurately in circumstances where if I tick middle-class or similar, my legal position will be much weakened relative to marking myself as lower-middle or working class, whether it is true or not. Just how blunt an instrument would that be?

And then as employer, if all the other bits of the legislative jigsaw have somehow been rammed into place, on what criteria am I actually okay to make my recruitment decisions without thereby betraying direct or indirect class prejudice? How do we separate convincingly the soft-skills aspects of the person’s presentation from considerations of class? Is a dropped t or an elongated vowel the product of background or affectation? Is the TUC suggesting, for example, that class discrimination should also contain an equivalent to s15 Equality Act, where if I treat you less favourably by reason of “something arising out of” your disability/class I am liable unless I can show that treatment to be the proportionate pursuit of a legitimate aim?

Even if you could (which you patently can’t) take the view that all job interviews can be determined solely on objective criteria, and even if X scored lower than Y but still got the job, that still takes Y nowhere unless he can show that X either is or was perceived to be in a different class, however defined, from Y. Where trends and fashions are so ephemeral and issues of class are so often claimed or disavowed by individuals as it suits them, that is basically a non-starter.

Reducing social disadvantage is a very laudable aim, but this is not the way to do it, at least not without a very great deal more thought given to it than the TUC has managed this far.