The performance of failing teachers can also rise to unexpected heights if headteachers are prepared to do some heavy breathing and make it clear that things need to improve, he says. But the culture of the education service makes it difficult for heads to tackle underperformance early on and means problems are allowed to fester, sometimes for years. Mr Curtis is something of a poacher turned gamekeeper - he was once a regional officer for the National Union of Teachers and is now director of the education personnel consultancy, EPM Ltd.
Referring to proposals from local government representatives for a new fast-track procedure to make it easier to sack teachers than other employees, he says: "It's the culture that needs to change, not the law. You can change all the laws in the world, but if people aren't prepared to take action against underperformance, the law won't make any difference."
Bev Curtis also questions whether industrial tribunals would regard as fair dismissals based on a proposed new charge of "gross incompetence". It is more likely, he says, that they would ask what steps had been taken to improve a teacher's performance before it declined into gross incompetence. If a problem had been allowed to continue for some time, they might take the view that it was not only the teacher's capability that needed to be looked at - but also that of the headteacher and his or her advisers, who had clearly failed to manage that individual effectively.
Bev Curtis and his co-director Maureen Cooper, who together took over Cambridgeshire County Council's educational personnel department in a management buy-out, are equally critical of proposals to give local authorities new powers to start disciplinary action against failing teachers. They say that a minority performed badly long before the days of local management of schools. Education's management culture has never encouraged anyone to tackle the problem, either when LEAs had more power or since they have had the chance to influence school governors through the advice they provide.
David Hart, general secretary of the National Association of Head Teachers, also argues that local authorities are part of the problem. It makes no sense, he says, to devolve responsibility for raising standards to individual schools and then give LEAs the power to intervene when they do not like what heads and governors have chosen to do.
Describing as outdated the view that it is headteachers and school governors who are reluctant to do anything about failing teachers, he adds: "In some cases the local authorities who want these enhanced powers are giving advice to heads that is forcing them to be overcautious.
"It is local authorities who are still so frightened of the activities of unions that they tend to back off and try to fudge settlements, rather than go through with the procedures that are there to be used."
But Mr Hart agrees that there are difficulties with existing competency procedures - which Bev Curtis says include
so many different stages and are such
an obstacle course, that heads and governors have neither the will nor the stamina to use them.
EPM recommends schools begin with an informal stage early on, which carries no right of appeal but allows headteachers to give advice to teachers whose work is not up to speed. This advice is reinforced by a warning that things need to be taken seriously and put right.
If this approach does not bring about an improvement, the individual receives a first written warning, followed by a final written warning before the matter goes to a dismissal hearing before the governors. Each stage of this later, formal procedure carries a right of appeal.
The teacher needs to be given targets, support and a reasonable, though not excessive, time to improve.
Bev Curtis and Maureen Cooper believe that if there are fair but sensible procedures in place, it becomes reasonable to expect headteachers to use them as a management tool. But heads must feel confident that they understand the procedures; to gain this confidence they need more personnel management training than at present.
"There is this strange belief that schools are about managing the curriculum, and as long as you can manage the curriculum you can manage the people who deliver it. But the two things are completely different," says Mr Curtis.
Primary teachers, especially, are unlikely to have had much experience of managing people before they become headteachers and need specific personnel training if they are to tackle the problem of underperforming staff.
All headteachers also need ready access to good quality advice, and here EPM does see an important role for local authorities. With the bulk of their education budgets now delegated to individual schools, not all LEAs are able to maintain a full education personnel function, but Mr Curtis says there is no reason why they should not "kitemark" approved personnel consultants who could guide heads and governors through what is often viewed as the minefield of capability procedures.
But heads should be prepared to tackle underperforma nce at an early stage. If they allow failing teachers to continue to damage children's education for years, then the individuals concerned will quite reasonably ask why they are suddenly being picked on. That is when a legal challenge becomes likely.
"The main thing to get across to people is that managing underperformance is not fraught with dangers and difficulties if it is done properly," says Mr Curtis.
"If you start from the point that you are not trying to dismiss the teacher but trying to improve his or her performance, then you've got a chance of succeeding."