The introduction of a new wave of grammar schools should not go ahead without investigating any impact on the teacher supply crisis, education recruitment expert John Howson has said.
Prime Minister Theresa May is expected to give the green light for a new generation of grammar schools next term, with a decision to scrap the ban on new selective schools.
But now Mr Howson, an honorary research fellow at the University of Oxford, has pointed out that the effect of increased selection on the teacher workforce is unknown.
“For existing secondary school teachers, the question is simple: if your school were to lose 30 per cent of its most able pupils, would you continue to teach here?” he writes in his latest blog post.
He also suggests asking potential teachers whether they want to teach in a school where 30 per cent of the age range do not attend.
'On the brink of a catastrophe'
Unions have already warned that schools are struggling to find enough teachers, with Mary Bousted, general secretary of the ATL, saying that the recruitment crisis is in danger of becoming a “catastrophe”.
Mr Howson said: “Making a teacher supply crisis worse won’t help the education of those not selected for a grammar school place.”
Malcolm Trobe, interim general secretary of the Association of School and College Leaders, agreed that the impact of more grammar schools on teacher supply is an important issue.
"Most teachers value the opportunity to teach across the range of ability, so there is an inherent risk that people would not want to teach in institutions in which they don't have the opportunity to work with students who aren't academically as able. They may seek alternative careers," he said.
"Justine Greening [education secretary] has two major priorities: addressing teacher shortages and school funding. She needs to prioritise, and dealing with recruitment issues should be top of her priority list. To look at making structural changes to the school system which may well have a detrimental impact on recruitment doesn't seem to be a sensible step at this stage."
The Department for Education was criticised by the National Audit Office earlier this year for its lack of information on teacher shortages, which included not knowing the local picture on teacher shortages and whether its teacher supply model was accurate.
While the DfE workforce census results do not list vacancy rates by school admission policy, teachers in non-selective schools are more likely to take time off sick than those in grammars, according to a recent analysis of sickness rates in schools by education data specialist SchoolDash.
The analysis found that grammar schools lost far fewer days to sickness than non-selective schools in the 2014-15 school year – with 53.3 per cent of teachers taking sick leave during the year in grammar schools compared with 59.8 per cent in non-selective schools. The average number of days taken off sick was 5.6 in grammar schools compared with 7.3 in non-selective schools.