The school has also made both its full-time counsellors redundant and increased class sizes to cope with the shortage of money.
Mr Rowe said: “In addition to these cuts, the school has also had to absorb teacher salary increases as well as a significant proportion of the SEN (Special Educational Needs) funding previously paid by local authorities.”

He said the loss of counsellors was of particular concern because of the rise in mental health issues.
According to Mr Rowe, teacher salary increases at the school have risen by about £300,000 over the past six years and special needs funding has cost the school £130,000.
A charity set up raise money for the school has had to run dinners at which parents are asked to make financial contributions to help run the school sufficiently.
The school, which is one of the top five non-selective schools in the country at both GCSE and A level, said its annual budget has fallen from about £4.9 million to £3.9 million between 2012-13 and 2018-19.