Concerns over the smaller number of new graduate teachers to fill some roles and the increasing number of teachers quitting the profession has increased demand for experienced supply teachers, Giant claims.
Department of Education figures from December 2012 showed that 47,700 teachers left their jobs in 2010-2011, up 19% from the 40,070 that left their jobs the year before.
According to the report, supply teachers are also reporting shorter gaps between assignments, with 86% of supply teachers surveyed reporting waits of less than a month between roles, up from 79% in 2011.
The report also states that better pay is becoming an increasingly important factor in teachers decisions to move from permanent roles to temporary ones.
The most popular reason for choosing to become a supply teacher - lifestyle - slipped from being the top choice of 56% of supply teachers in 2011 to 47% in 2012.
Matthew Brown, managing director Giant, said: "With a drop in the number of new graduates entering parts of the teaching profession as well as an increase in existing permanent staff leaving the profession, a teacher shortage is being created.
"This shortage means plenty of opportunities have arisen for supply teachers over the last year, and these opportunities will continue in 2013. Schools are increasingly in need of experienced supply teachers to plug staffing gaps, which is pushing teachers' daily pay rates up."
