Labour’s confidence that it can recruit more teachers and retain more is seriously misplaced if the only things it has to offer are more training and a strategy of paying a bonus of £2,400 to teachers who have completed the Early Career Framework.

Quite rightly, the Chartered College of Teaching has called for plans to retain teachers at other stages of their careers. While the £2,400 is a pleasant welcome to teaching on top of a starting salary of £30,000, with even better “golden hellos” for teachers of shortage subjects, it leaves quite a desert of expectations beyond.

Arguably, all that the two main political parties will have achieved in their respective workforce policies is to make the first three years of teaching financially attractive and incentivise young teachers to pocket the cash and move on to a more lucrative occupation thereafter.

While some will argue that teaching could sit well within a portfolio career, the system needs professionals who are in it for the long haul.

A plan for experienced teachers

There are compelling reasons why more effort is needed to retain the “forgotten middle” - the two-thirds of teachers who remain.

If you demotivate longer-serving teachers by constantly imposing lower pay increases on them than for new recruits, you will ensure that their experience is lost to the system. To keep replacing departing teachers incurs three years’ worth of training costs for each one, and temporary supply agency fees to fill increasingly numerous gaps during the year.

Preventative action makes better financial sense.

Also, a school staff that has a good balance of new recruits and longer-serving teachers provides greater stability. From their ranks come the mentors who will pass on their knowledge and expertise to the next intake of beginning teachers. In some establishments, mentors are also there for other staff who want to improve their practice and career prospects. In a situation where the system needs more beginning teachers, mentoring capacity must be maintained.

Perhaps the most important reason for improving the prospects of the neglected middle of the profession, though, is that this is the pool from which middle and senior leaders will be drawn.

Inevitably there are more vacancies for headships left unfilled and younger, less well-prepared staff take on these onerous responsibilities.

School leadership pipeline

The government strategy of a much flatter pay structure with smaller increases between points on the pay spine may save money that can be allocated to the higher starting pay, and thus keep the whole wages bill within a highly restricted budget. But such a strategy sends the message that experienced teachers are not valued.

Labour is simply reinforcing this message. The opposition needs to go much deeper to tackle the retention crisis and ensure fair pay for all.

If Labour wants to see schools led by confident, experienced heads who can stay in post long enough to oversee improvements and to weather initiatives, it must recognise and reward the huge contribution of middle and senior leaders, and so make the roles worth aspiring to.

Workload is part of the answer. Too many heads are overwhelmed by excessive workload. But a pay structure that robs Peter (the experienced middle) to pay Paul (the new recruits in their first three to four years) is not a suitable long-term strategy.

All the promises of greater flexibility - and undefined benefits from an artificial intelligence of as yet unknown capability - count for nothing if the job remains so deeply unattractive.

Yvonne Williams, who has been teaching for more than 30 years and was a member of the Department for Education Marking Policy Review Group, which looked at teacher workload in 2015-16