Thousands of cash-strapped teachers are opting out of pensions because of an increase in monthly contributions, while schools could be forced to cut staff to balance their books.

A document seen by TES reveals that the number of teachers quitting the Teachers’ Pension Scheme (TPS) between April and August 2014 increased by 46 per cent from the previous year.

Over half of those who left the scheme cited “personal financial reasons” for their decision. Over the last decade, teachers have faced a real-terms pay cut of more than 10 per cent.

Andrew Morris, head of pay and pensions at the NUT teaching union, which has held several strikes over the pension reforms, said the rise in the number of teachers opting out of the scheme was a “worry”.

Schools will also see their TPS contributions increase by 2.4 per cent in September. Headteachers have warned that this change, combined with a rise in National Insurance bills the following year, could force them to cut staff to save money.