David Cameron has given us five years to finish the job of restoring schools to their proper purposes.  Conservative ministers under the coalition abolished almost all of the quangos, rewrote the national curriculum, got rid of fake qualifications, reformed examinations and gave schools a realistic alternative to local authority control. Extending the role of the national college to teaching as well as management has set up a viable centre for research based on what works.  Subject reforms in maths, early reading and the teaching of grammar were put into action, and the very successful move from information and communications technology (ICT) to computer science is being studied by other European governments. We need similar work in all other subjects.

Nicky Morgan has taken the next key step by using the election victory as a basis for tackling the problem of coasting schools by targeting their headteachers.

A school coasts when headteachers give priority to social goals rather than standards. A London head was very open about this at a Westminster Forum meeting last year, defending his mixed ability policy in all subjects except maths as a way of avoiding telling pupils – he of course calls them students – that their “attainment” was the only thing that mattered.

Mixed ability teaching hinders progress by making it more difficult for teachers to match work to the learning needs of individual pupils, and in his case the languages results showed up the problem, with minimal take up at A level.  Ofsted has linked mixed ability teaching with low achievement among higher attaining pupils – some heads didn’t even know who these were – and my own observations, carried out using the same criteria in London secondary schools, showed that struggling pupils were hit harder still.  These pupils need more explanation, more practice and more time to think. If they are given work they don’t understand, they become frustrated, and then angry.

Corporal punishment apart, the power of heads is very close to that exercised by a captain in Nelson’s navy. Heads’ references can make or break careers – a head once boasted to me that she had written a dishonest reference to remove an under-performing head of sixth form – and they have all manner of administrative devices at their disposal to make a person want to leave, or to stay. A head decides that PE staff are not allowed into the staff room at break unless they change into suits – so be it, and it’s not his problem if people can’t change twice in fifteen minutes. He doesn’t like someone’s attitude, even though he has a high-performing department, ditto.  Governors can ask questions, but most appointed the head in the first place, so don’t do so.

Fake equivalences and unreliable data have made identifying coasting schools more difficult, and  only the return of external examinations will reliably identify underperformance. Honest headteachers have had to compete with those who gave all of their pupils a “five higher grade passes” ticket by putting them on courses that award four of them for one subject.  Rough justice – by which I mean inspection based on data rather than first hand observation – will hit these honest headteachers rather than those who deserve it.

Therefore we also need to improve the quality of inspection, and to get rid of the idea that any inspector can inspect anything.  A languages head of department told me last year that an inspector who didn’t know anything about languages picked out the weakest pupil in the class as “seeming to do very well”.  You can’t inspect what you don’t know, and Ofsted’s move away from subjects as a basis for inspection needs to be reversed.

So, there is a great deal to do. Fortunately, we have ministers, notably Nick Gibb and David Cameron himself, who have been through the mill and know what does and doesn’t work, a move in Ofsted to remove the influence of sub-standard inspection companies, and a secretary of state with strong understanding of finance. At an election hustings, I asked how Cambridgeshire’s education services had come to be under-funded for so long, and what candidates would do about it. Lucy Frazer, our new MP, said she’d say what she had already done – obtained £26m for Cambridgeshire schools from Nicky Morgan. We now know that Ms Morgan has provided similar help to 69 other authorities, reversing Labour’s policy of penalising them to subsidise its heartlands. Times are changing.