The supply teacher market in UK secondary schools has declined by a quarter as head teachers have turned to less costly cover supervisors, according to Mark Weavis, managing director of national supply teacher agency Teaching Personnel.

Weavis told Recruiter: "It is clear that the overall secondary market for supply teachers has declined significantly. Anecdotal evidence from a wide selection of schools suggests this decline is matched by an increase in the use of cover supervisors, who are not qualified teachers. A reasonable estimate would be that since 2005 the market has declined by 25% due to cover supervision."

Weavis added: "We believe that head teachers have opted for cover supervisors exclusively on the grounds of cost saving." According to Sarah Carroll, team leader at Now Education in Birmingham, cover supervisors are "at least 40% cheaper" than qualified teachers.

Yas Sufi, managing director of Beacon Teaching in Blackburn said: "A lot of schools look for the cheaper option, and those agencies providing them with supply teachers have suffered."

Stephen Ashfield, managing director of SAS Teachers, in Durham, said many schools prefer to employ teaching assistants, sometimes for up to eight weeks.

John Dunn, chair of the Recruitment and Employment Confederation's education sector agreed that the use of cover supervisors was an issue.

However, Dunn urged recruiters to be flexible in adapting to a new market which, in addition to requiring qualified teachers, now included teaching assistants and administration personnel. "To thrive in this environment, recruiters must reflect this new diversity," he said.