Technically, as a political appointee he is't allowed to tell other civil servants what to do. In fact, his status is closer to that of a minister. Should he get the job the downside will be reverting to plain Mr Barber. As his secondment from the Institute of Education formally ends, he will lose his claim to be called professor.
NEW term, old job. Most people expect Professor Michael Barber to have an advantage over other applicants for the head of the standards and effectiveness unit at the Department for Education and Employment, particularly as he is already doing the job.