I’ve been a teacher for 13 and a half years, both as a middle manager and full-time teacher. And, without any hesitation, I can say that what teachers need is not more money, but more time. By that, I mean time to plan, to assess, to monitor, to measure – and to think.

In my current school, there are 25 teaching hours a week: three of these are protected planning, preparation and assessment (PPA) time. I’m an English specialist which means that I teach a subject which is particularly heavy in terms of marking. If my class of 30 spends one lesson writing an assessment, each of which will take (at a conservative estimate) 15 minutes to forensically mark, meaningfully annotate, and carefully record – that generates around seven hours of marking. That’s close on a whole working day.

On average, our schemes of work require an assessment at least once a half term. If I am working full time – which means 22 teaching hours a week with six classes – I should be picking up that seven hours of assessment once a week from one class or the other.

And then there are the class notes of students, which need to be acknowledged, have spellings corrected and thoughtful marking comments or questions added at least once per half term, then my average weekly marking load appears to be around 15 hours a week, or three hours of every day.

I arrive in school at 8.30am and teaching finishes at 3.40pm, so if I remain in school until 6.40pm every day, I should clear the lot, right?

Wrong.

Because this notional figure fails to take into account the phone calls home, detention logging, liaising over vulnerable students, planning lessons, writing reports, attending meetings and twilight inset, and responding to various emails that I am obliged to do on a daily basis. It also assumes that after five hours of teaching a day, I have a fresh, empty mind capable of competent, high-speed marking.

It just doesn’t add up.

The solution is simple, but probably more expensive than schools – or government – are willing to pay.

Give teachers more time in their allotted working hours to do the bits of their jobs which don’t involve standing in front of a class. Primary school teachers have a day a week for PPA, a fifth of their working time, with teaching assistants and parent helpers around to support them. And yet they are still under huge time pressure. How can anyone think that a full-time GCSE/A-level English teacher can survive on three hours' PPA a week? Or that a PE teacher, who regularly gives up their lunch breaks, weekends and after-school time, can plan lessons, mark and monitor work and arrange matches in that time?

I would propose the following:

Give every teacher at least 20 per cent of their working hours as non-contact time. Identify subjects with heavy marking burdens – English, humanities, etc – and give them 25 per cent.

Give larger departments an administrative assistant so teachers aren’t following up book returns, stamping new textbooks and photocopying, let smaller departments share an administrative hub. Give all teachers access to a working, good quality printer. Make a space and time every week for departments to meet and discuss their experiences, share good practice and relay their frustrations. Make all teachers feel valued.

The need is clear. Teachers are not bankers, administrators or accountants. No, we are tasked with shaping future generations. We are expected to transcend parental and social influences, change hearts and minds and produce a workforce with the values and beliefs society desires. We are supposed to counteract the hours young people spend on technology every evening, and we are then obliged to deal with the messes they get themselves into using tech.

Investment in teaching is investing in a shared future. And it is vital that we invest wisely.

I, like most teachers I know, constantly feel that I am getting through at work. To the next half-term, the next weekend...sometimes the next lesson. And there is always the expectation that at some point – some magical, wonderful point – we will be able to act proactively. Be on top of all the marking (as if). Be able to plan, differentiate, assess and monitor students like we want to: and like we should. Because that is what students deserve, and need, to become the people we, as a society, want them to be.

All teachers need is more time.

Katie Steele is a secondary English teacher in Hertfordshire