Your research on how schools and local authorities deal with incompetent teachers could not have come at a better time (“Failing teachers left in post by half of LAs”, November 12). In many instances, we are seriously letting down our children and teacher colleagues by not dealing expeditiously with the minority of incompetents in teaching.

So what are the impediments? First, it is extremely daunting for headteachers and governors to sack an incompetent teacher. Apparently, this is not the case in industry. Reasons that headteachers have mentioned to me for this situation in England include:

- employment legislation in education makes it very difficult;

- the teaching unions are militant;

- school leaders are afraid to grasp the nettle;

- when school leaders begin proceedings against incompetents, they go off with stress, depression or both.

At a school I know well, the new headteacher had a baptism of fire because she decided to take on incompetent teachers who had had it very easy over the previous decade or two. The support of the local authority helped. However, the cost was astronomical, resulting in her and her governors having to deal with a budget deficit of #163;150,000.

David Sassoon, Director, Schools Support Services, London.