A barrage of emails from 'aggressive' parents is wearing down teachers, a survey claims.

The poll indicates seven in 10 teachers have had their email addresses passed on to parents – of whom 90% said this had been done without their permission.

This has led to an unreasonable expectation that teachers are available at all hours, according to the NASUWT union, which conducted the survey.

Of the 1,500 teachers polled, 14pc said they are expected to communicate electronically with parents in their own time every day while 19pc said they were expected to do this on a weekly basis.

One teacher said: 'The expectation in the school is that a reply to all emails will take place within a reasonable timeframe, if it is from a parent, and if there isn't a reply then a senior leader gets involved and there is a reprimand that teachers should reply to parents ASAP.'

Another commented: 'The communication with parents via email has become unbearable and I am resigning from a pastoral position as a result.

'Parents may be rude and aggressive in emails (and staff may be too at times) and parents expect to be able to contact teachers 24/7.'

NASUWT general secretary Chris Keates said: 'Teachers are not just facing the intrusion of those who manage them into their private lives but there is now an unreasonable expectation that they are available at the convenience of parents.'

The poll found only 5pc of teachers did not receive work-related emails outside of school hours, with 15pc receiving them while off sick.

Teachers also reported being emailed while on maternity, paternity or bereavement leave.

More than a quarter (26pc) of the respondents said their email or online activity was monitored by their school.

Ms Keates added: 'Rather than helping teachers to work more efficiently, email abuse is instead electronically tethering them to their classrooms, adding to their stress, anxiety and workload.'

In January, education secretary Damian Hinds said teachers should shun the email culture in a bid to reduce their workload.

He called for them to ditch emailing outside of office hours and instead make smarter use of technology, both inside and outside of the classroom.