A new system for checking teachers could lead to a time gap of at least a month between the application for a check and the school or agency receiving any information.
From the end of February requests to the Department for Education and Skills for List 99, the teachers' blacklist, will be referred to the Criminal Records Bureau, which will also hold police files.
But employers will not be able to get access to the bureau's records until April at the earliest, leaving a worrying hiatus.
Local authorities and teachers' leaders have complained about the slowness of the present listing procedure. The DFES receives more than 100 cases for investigation every month and may take months before reaching a decision.
Schools, local authorities and supply agencies can access the list which has 2,500 names, included after department investigations, which are usually prompted by a complaint from employers or police. It does not include those facing criminal charges.
Reasons for inclusion are:
* the need to safeguard children where there is a risk to their welfare, or where the teacher is presenting an "unacceptable example";
* failure to uphold high professional standards;
* to protect schools and the education service from fraud.