The grammar school debate is firmly back on the agenda thanks to a burgeoning campaign by Conservative MPs to lift the ban on new selective schools. But bringing back selection is no substitute for the one silver bullet in education: good teaching, argues Russell Hobby.

Grammar schools have returned to our political debate, and I am hoping they remain a topic of debate, filling the summer gap, rather than an item of policy.

But there is always a risk that momentum will grow behind the idea, so it is worth addressing the argument now. Why do we keep returning to it, all evidence to the contrary?

Politicians deal in symbols. And grammar schools have become for some a potent symbol of social mobility and meritocracy.

No one would accept a new clinical procedure on the basis that that it worked for a politician when they were younger

But our children don’t need symbols. They need reforms with a proven impact on standards. No one would accept a new clinical procedure on the basis that it sounded good. Or that it worked for a politician once when they were younger.

They would demand credible independent evidence. We should set the same bar for education reforms.

And on grammar schools, the evidence suggests they do not increase social mobility and they do not raise academic standards overall. They make things a little better for a few and a lot worse for many.

While grammar schools themselves produce better exam results, the attainment of students at secondary moderns in areas where selection still exists is lower than those at comprehensives in areas where grammar schools do not exist. Perhaps 50 years ago we could afford that equation, but in the twenty-first century we need high standards for every pupil.

The worst of it is that grammar schools do not favour the ‘poor but bright’. Evidence suggests that they often take far less than their share of children from disadvantaged backgrounds. Research in 2012 showed that the majority of remaining grammar schools took less than 3 per cent of pupils eligible for free school meals – many took less than 1 per cent.

Symbols all too easily become expensive distractions, providing an attractive substitute for incremental gains and essential investment. The debate over grammar schools has been had. To rehash it now would draw attention away from the real challenges our education system faces. There are many other things that need our time and our money.

There may be one silver bullet: good teaching

I always used to say that there are no silver bullets in education. I think that there may, in fact, actually be one silver bullet: good teaching.

Good teachers help all children but disadvantaged children benefit more than anyone else because they often lack the family resources that could compensate for poor teaching. But regional variations in funding and recruitment are increasingly creating serious barriers to matching talent with need.

The test of every policy should be this: does it put more good teachers in front of the children who need them most and does it help those teachers thrive? Grammar schools, in practice, do not.

Helping teachers improve and encouraging them into our toughest schools is a simple idea but a difficult task. It doesn’t seem to be a potent symbol like grammar school education because it requires a whole network of small, slow unglamorous policy changes. But these changes would add up to a huge difference.

Automatically registering eligible children for pupil premium funding, for example, would target resources for great teaching more accurately. And giving pupil premium students a head start in the admissions queue, immediately behind looked after children, would also counteract the forces that slowly crowd them out of successful schools.

Paying teachers properly and treating them well will create a larger pool of talent and focusing on progress rather than raw attainment would attract that talent where it is most needed.

We need – and our children need – real improvements, not symbolic action.