he would say that, wouldn’t he?” The famous quotation from Mandy Rice-Davies infects the debate about teacher shortage. Government ministers, most recently Stephen Timms, have an interest in talking down the extent of the problem, while teacher unions have an interest in talking it up. Is this a crisis and, if so, what can be done about it?

We have been here before. In 1990, at the height of the last economic boom, the recorded vacancy rate in secondary schools was 1.5 per cent compared with 1.4 per cent now, according to the Government’s own statistics. Never mind that the Department for Education and Skills has cast doubt on its own figures for 2001, the survey published last week by The TES and Secondary Heads Association confirms that the secondary situation is deteriorating fast, with secondary vacancies alone up from 4,000 to 5,000 since last September.

We could take a relaxed attitude on the basis that a downturn in the economy, and in graduate employment opportunities, is inevitable sooner rather than later. Indeed, just three years after the peak of 1990, secondary vacancies had reduced to 0.3 per cent. There are three problems with this.

First, the Government’s own view is that both the economy and employment will continue their steady growth. It would be a little strange for the Government to base its policy on teacher supply on a judgment about the economy that it is completely wrong. Secondly, over the next three years, an extra 118,000 secondary pupils will be in schools because of a rise in population. At current staffing standards, that will require an additional 6,900 teachers. Thirdly, the Government is committed to increasing spending on education by 5.4 per cent a year in real terms for the three years to 2004. Funding is the major driver of teacher demand and we may assume that - as long as the choice remains with headteachers - the traditional pattern of staff-intensive spending will continue.

While the trend towards increasing all kinds of support staff will grow, extra teaching posts will take most of the new money. Furthermore, the additional “pressure and support” that the Government has promised for secondary schools in its second term will produce yet more new jobs. Indeed, this explains why both sides of the argument are correct: numbers employed have gone up quickly, and so have unfilled posts.

If the promised increase in funding were to be spent in current proportions, we would need 70,000 additional teachers by 2004, most of them in secondaries. In contrast, Labour’s manifesto pledge was for 10,000 extra teachers; this represents a minimum.

The present difficulties are due to between 2,580 (according to the DFES figures for January) and 5,000 secondary vacancies (according to The TES survey). On present trends, then, secondary schools are in for a difficult three years. Thereafter, decreasing pupil numbers will provide some relief. This would be offset, however, by any further policy decisions to increase education funding. Even more importantly, it will be offset by the retirement of the 45 per cent of teachers now in the final 15 years of their careers.

The upturn in recruitment to postgraduate teacher-training is welcome news. Unfortunately, the latest available figures (for the cohort finishing training in 1998) show a loss between entry to training and entry to the profession of 40 per cent; and any increase in entrants can have only marginal impact on the immediate difficulty. But the situation is far from hopeless. There are two sources of extra teachers in the short term. First, in 1999, more than 26,000 teachers drained out of the profession for reasons other than retirement. Second, in 1999, there were 71,200 people in England not employed as teachers but still aged under 50 and with experience within the previous six years - 33,000 of these were secondary teachers. Perhaps 20,000 of the latter could be persuaded to return. How do we maximise this figure?

Teachers are spending too many hours doing the wrong things. The Government must ensure that a realistic proportion of the working week is set aside for lesson preparation and follow-up. It must find a way of promoting the concept of teacher time as a scarce resource, to be managed with care. It must make a judgment about reasonable working time.

The Government must re-examine the excessive controls and demands made on teachers. This lack of trust in teachers’ professionalism has led to fatuous recording of future and past activity and a morale-sapping perception of loss of autonomy.

Research evidence is quite clear: teachers are motivated by the intrinsic nature of the job. As soon as the job improves, we shall encourage more to stay or come back. In the longer term, we must look at degree subject requirements, support for those in career breaks, and measures to make the profession more representative. For now, it is retention which is the key to finding the teachers we need.

Martin Johnson is education researcher at the Institute for Public Policy Research. The report is available at www.ippr.org.ukresearch