Ben Gadsby is an education policy specialist, and a former chairman of Thurrock Conservatives.

The post-school education landscape is filled with competing interests. The needs of big business v the needs of small business. The needs of the current economy v the needs of the future economy. Value for money, cost, and who should pay.

These discussions always start with higher education – the most visible and well-defined part of the landscape. A classic example of this is the Augar review of post-18 education. Covering both higher and further education, the academic and the vocational, it is invariably written about as if it’s all about students, whose turnout in 2017 was for a time the preferred reason for a less than successful election.

Which is why we always start with discussion about tuition fees and student debt. Indeed, Anna Firth recently wrote on this site about how they “disenfranchise millions”. But this isn’t a good place to start, because levels of access to university have actually continued to go up, not least because most young people know that the “debt” we’re talking about here doesn’t operate like debt in any normal sense of the word.

Far from disenfranchising millions, it’s actually a clever system. If a young person goes to university, gets a maths degree, and then makes a small fortune in the city, he or she will probably pay off the costs of their degree, leaving the taxpayer with no cost at all. The same young person opting to teach pays less, but contributes. The same young person who ends up working two days a week because they spend the rest of the time caring for a disabled relative pays nothing. And no-one ever ends up seeing a bailiff, regardless of what they do or don’t pay.

And this, surely, is almost exactly how we would want the system to operate. Because to unleash Britain’s potential, we want a well-educated workforce ready to compete in our globalised world. Britain is not unique in this regard – top ranked South Korea gets 70 per cent of young people educated to degree level, compared to 50 per cent here. We’re also behind Ireland, Canada and Australia and only one place ahead of the US. And unlike the US, we have a financing system that ensure the more you benefit from it, the more you pay back.

The next discussion we usually get into, most recently represented on this site by Julian Brazier, is some variation of the idea that too many people are going to university. It seems that not all Conservatives have as yet concluded that Britain should, like its competitors, invest heavily in a graduate workforce. In Julian’s case, this article took that form that the system is “failing those with lower attainment levels” because they “lack the academic skills to benefit from a purely academic degree”. I don’t think there’s much future for a party that takes this approach.

Take the often-quoted statistic about the number of graduates in “non-graduate” jobs. It sounds like a compelling argument against expanding higher education – until you realise that a civil service promotion can see you move from a “graduate” job to a “non-graduate” one, and there are “non-graduate” jobs that require a degree. Lies, damned lies, and statistics.

There are similar issues with the topic of graduate salaries. Going back to my maths example, the course that resulted in a maths graduate going to work in the city was more successful and valuable than the one that produced the maths teacher. And both were more successful than the course that the carer took. And if all went to the same university, we’ll judge the course based on their average salaries, and judge the courses that produce the most city types as the best. We must be careful not to know the price of everything and the value of nothing.

But even if you believe that the system is failing those with lower attainment levels, and even if you believe the alternative is to boost further education (which is a good idea), the conversation always turns to further education courses that require a higher standard of entry than some degrees.

This in a way is the most damaging part of the whole higher education conversation right now. Because everyone seems to be so busy trying to invent vocational alternatives to degrees that they’re completely forgetting about the qualifications on offer for the young people who are not going in a degree direction anyway.

Let’s design an apprenticeship system that offers higher and degree apprenticeships, as an alternative to higher education – great! Then watch the number of starts in apprenticeships at GCSE and A level equivalent fall. Let’s create T levels as a vocational alternative to an A level, pitched at the same level – great! And what exactly do the one in three young people who aren’t ready to move on to A levels or T levels at age 16 do instead?

Seriously, that’s not a rhetorical question, that’s a thing that the Department for Education really needs to get a handle on if unleashing Britain’s potential is actually meant to amount to anything. In the Robert Halfon ladder analogy, the problem we have is with the lower rungs. And yet the perceived wisdom is that it’s the higher education system that’s “failing those with lower attainment levels”. Of course, that argument uses the phrase “lower attainment” to mean the people at the bottom end of the top half.

What are to do with this these young people, who are above average attainers, and who competitor nations would aim to educate to degree level? The case seems to be that our MPs in red wall seats should tell families of young people who have worked hard to become the first in their family to go to university that their children won’t benefit. Tell them that actually, unleashing Britain’s potential means that their “lower attaining” children need to do a vocational option with a higher entry requirement instead. This might make for an interesting documentary, but I fear it would have to be broadcast after the watershed.

This is all much less complicated than it sounds.

If we want to be a top performing country with a high skilled workforce ready for an increasingly automated world, we need to send at least half of our young people to university.

It is entirely sensible to fund the costs of that in a way that means any young person who is qualified to take that route can do so without taking on a huge financial risk – and also limits the extent to which my non-graduate sister is subsidising my degree.

And we need to stop obsessing about vocational alternatives aimed at that same top 50 per cent of young people who already have the option to go to university, while ignoring the needs of the other half and in particular the bottom third. Because my sister isn’t just a non-graduate. She got a D in GCSE maths (twice). She’s the one who I reckon the system has failed.

One of the joys of writing for ConservativeHome is you hope to have an influential audience. If you’re an influential person reading this, please could you remember that the mission of unleashing Britain’s potential ought to include my sister?