Well done Ms Morgan for paying attention to the women in their late 20s and early 30s who leave teaching. Losing their expertise is a problem for the teaching profession.

Yet, like a toddler playing a game of hunt the thimble, you are very, very warm, but having located the problem, you have adorably veered off in the wrong direction as you fumble around for the solution. The issue is not that teachers (of both sexes) need opportunities to work part-time or flexibly, laudable though that proposition may appear on the face of it. In our profession, which is quite different from many other professions, that is the wrong answer to the correct question.

The nub of the problem is this: teaching in England has swollen to become a 60-plus hours a week job and that is impossible. It is also unsustainable and extremely detrimental to children’s learning outcomes, however one decides to measure them.

I know many teachers who have opted for part-time employment and so work (and are paid) for four days’ work each week. Typically, in addition to working at school from 7:30am till 5pm on their ‘employed days’ (15 minutes for lunch), they spend a couple of hours a night marking and planning at home AND they come into school on a Friday to get resources etc ready for their upcoming lessons on Monday. They have opted for a four-day a week contract so they can take the weekend off and focus properly on their families. Let me be clear, they are paid a four-day wage in exchange for five days’ work.

Likewise, teachers who are paid to teach for three days a week actually complete 35- to 40-hour weeks. I know this because I used to be one of them. (Meanwhile, they also suffer all of the career-progression blockages experienced by part-time workers in any field, which makes the prospect of part-time work yet more unattractive. Again, I know this because I was one of them).

It is not inevitable that teaching is a job that should take up one’s evenings and weekends and this is the issue that needs to be addressed. It’s certainly not how Shanghai, Finland or Germany organise the working lives of their teachers. I’m a solutions-focused kind of person (no handwringing or “disingenuous claims” here), so these are my suggestions for how to go about sorting out this problem. The good news for you is that you only need to be involved in the first of these three strategies.

Teachers either need to teach fewer children (so there is less marking, etc, to do) or teach the same number of children for fewer hours (so they have time to finish their work within a nine-hour day). We’re losing state-school teachers to the private sector because that is exactly what the independent sector offers teachers. This would certainly cost money - but how much money are you wasting by haemorrhaging hundreds of teachers every year?

The amount of money that has been poured into sand since I started teaching in 1999 is extraordinary. I have lost colleagues and their expertise over and over again in every school I have worked in. Those of us who are aged about 40 and still standing, whisper in corridors about not being able to continue at this pace in 10 years’ time. We are excellent teachers at the top of our game and we are on our knees. Take heed. Eventually voters are going to make the link between their primary children (and grandchildren) being taught every year by an endless string of NQTs, their secondary children (and grandchildren) being taught by harassed non-specialists and your own mishandling of the profession.

Colleagues, we must prioritise in-class feedback. It works and it would reduce our marking load. We must take Ofsted at their word and hope that they will look for progress over time in children’s work and not lengthy evidence of dialogic marking at the end of every single piece of work. School leaders need to start gently telling off teachers who look like they’re providing evidence for evidence’s sake, not grading pointless overwork as ‘outstanding’. We should only mark and assess as much as we need in order to plan our subsequent lesson well.

And here, perhaps controversially, is why part-time teaching is difficult. If you work full-time, you can act on what you notice. “Ah, Josh has forgotten how to use his bonds to 10 to add to the next multiple of 10. I need to go back a step and do that with him tomorrow during the lesson/at break/during assembly.” If you work full-time, you can act on these thoughts.

Your options when you work part-time are much more limited, no matter how excellent your communication with your job-share partner. Good teaching is contingent and each lesson builds on what has gone before. Tomorrow’s lesson shifts its focus (or not) depending on how today’s went. If you’re there every day, that just becomes easier.

Since returning to full-time work, I can more easily make the most of these opportunities. What I need is to have enough time during my working day at school to do just-enough marking and the right amount of planning.

How did we let this happen? Were we sleepwalking? Where was our sense of ourselves, our professional backbone? This year, I have been involved in interviewing candidates for BEds, PGCEs and School Direct students. If they were to be accepted, the applicants had to convince us that they had the energy, belief and inner strength needed to be a good teacher. People go into teaching because they want to make a difference and because they realise there is no better way to spend your day than helping children to better understand the world they live in.

Teachers are leaving the profession because we are too tired and too restricted by politically-motivated shenanigans to recognise our passionate ambitions in what we actually have to do.

We need the system as a whole to work together to do two things: firstly, protect those on the front-line from unworkable diktats; secondly, we need to take a proper lead in how we train and develop teachers throughout their careers so we have confidence in our professional selves.

A more confident profession would present a united and robust defence to the rapid change and confused philosophy of recent developments in the educational system. And it wouldn’t go along with a solution to teacher retention based on accepting the exploitation inherent in teachers doing five days’ work for four days’ pay.

Retention is not about flexible working hours. It’s about too many working hours. Look, I’ve found your thimble for you.

Sinéad Gaffney teaches in Sheffield and is currently studying for an EdD at the University of Sheffield. @shinpad1

This article originally appeared on Sinéad’s blog, ThinkSayWriteCheck