The level of discrimination levelled against older teachers in schools has risen significantly, according NASUWT.

At its annual conference, the union stated that this has “become an increasingly serious problem”.

It claimed that there is “growing evidence” which suggests that older teachers - especially women - are being “singled out for redundancy or subjected to the abuse of capabilities procedures”.

Chris Keates, general secretary of NASUWT, said that older teachers have a “wealth of experience and expertise” that should be viewed as an “asset”.

“It is disturbing to find, however, that all too often older teachers are being targeted for redundancy, threatened unjustly with capability procedures, denied access to professional development, or subjected to excessive monitoring in an attempt to force them out of the school,” he told delegates.

“They face this harassment and discrimination often for no other reason than they are older and more expensive.”

Writing in TES last month, an anonymous teacher over the age of 50 noted how difficult it has been for her to find work, citing ageism as a key factor.

She said that she had experience, was a “dynamic” teacher and au fait with current teaching practice - nothing about her as a candidate would suggest that she was unsuitable for most roles.

“Age is relevant: not as a tool to persecute but as a reason to employ,” she said. “We live in an ageing society, full of people from whom we can learn but still struggle to appreciate. We must not shut them out.

“We need to embrace age, celebrate it for what it brings to a school, a classroom, a child. If we do, the world of education, and ultimately society, will be richer for it.”