It is such a good idea that I couldn’t believe I hadn’t thought of it when I first stumbled across it. How do you tackle the rise of permanent exclusions? Simple: instead of clamping down on how headteachers exclude pupils, you make those leaders responsible for the results of those young people even after they’ve been shown the door.

At first glance, the logic seems impeccable: school leaders won’t be so keen to chuck students out if their results are still included in the league tables. Indeed, they will be encouraged to do everything in their power to keep them close and fight for their education.

It’s such a good idea that it’s Labour policy, it’s already government policy and it’s a racing certainty to be the cornerstone of the imminent and long-awaited Timpson Review. Schools minister Lord Agnew has just confirmed as much.

The only problem is that it is very unlikely to work in practice. In fact, the more you think about it, the more problems it throws up, and the more clarity you get on why it wasn’t implemented by the DfE years ago.

The devil, as they say, is in the detail. In no particular order:

• What is the cut-off point before which an excluded student’s scores won’t be attached to a school? It obviously seems farcical for the results of a child who was excluded in Year 7 to be included in GCSE league tables. So where do you draw the line? 
• If the line was drawn at, say, Year 9, would that not potentially result in a rush to exclude any young person who looks likely to be a risk in the GCSE years ahead?
• Could civil servants create a system whereby a student’s results have a kind of reverse half-life in which a complex algorithm calculates a percentage of results based on the amount of time spent in the school? This seems unfeasibly complicated and impossible to both explain and police.
• Who owns the funding for these pupils when they are excluded? Such an idea would logically demand that the excluding head becomes the commissioner of alternative provision for the children they have removed, If they believe an AP is underperforming or not doing its job, then, surely, they should have the right to bring the student back into the school or seek another provider. Such a scheme is likely to be open to abuse.
• It will encourage gaming, not discourage it. For example, could such a policy risk encouraging a tiny minority of schools to keep such young people on roll but in internal isolation/exclusion, in the hope that their outcomes will be so poor so as to be disapplied from Progress 8 scores?

All of these are questions about the process, but a more serious issue I have with this policy lies in its foundations: it appears to be assuming that, currently, most schools are gaming exclusions. This is, in the main, not the case. 

Despite this, most of the solutions to problems thrown up by the policy are likely to disproportionately punish the majority of schools - those who strive to get the best out of even the most challenging students and for whom exclusion is a last resort.

There is one interesting coda. A potential reform that could make such a policy a great deal more workable: 100 per cent academisation. If all schools were in a multi-academy trust and all trusts had an AP provision, then many of the potential problems I have highlighted could be ironed out. MATs could be commissioners for their own AP and be held responsible for the results therein. But in the current political and policy landscape, the idea of universal academisation is for the birds.

As a result of all of these problems - and probably more that I haven’t yet considered - the likelihood is that this is a policy that will stay exactly where it has resided for years: on the drawing board.