teachers in Scotland are increasingly being subjected to cyberbullying from pupils, union leaders have warned.

Margaret Smith, president of the Scottish Secondary Teachers' Association (SSTA), said bullying of school staff on social networking sites was largely ignored.

Her comments came after a recent UK-wide survey by the Teacher Support Network charity found one in seven teachers had been cyberbullied.

Of these, 68% had received unpleasant emails, 26% had been the subject of abuse on websites and 28% had received abusive text messages.

The survey also highlighted the impact of cyberbullying upon teachers, with 39% saying they had suffered a blow to their confidence, 25% saying they felt the standard of their teaching was affected and 6% reporting they were signed off work with stress or other related illness.

In a speech to the SSTA's annual congress in Peebles tomorrow, Ms Smith will say: "We are only too aware of problems involving the abuse of social media networks and mobile phones among pupils, but far too little attention has been given to the cyberbullying of teachers.

"Make no mistake, there have been truly shocking examples of abuse of teaching staff by pupils from photographs taken without consent and posted on YouTube to false Facebook pages created filled with scurrilous content including explicit sexual imagery.

"I am convinced that the cases we hear about are the tip of the iceberg and that cyberbullying of teachers is an issue that the SSTA must confront head on."

Ms Smith will add that part of the problem is the fact pupils who misbehave are routinely returned to the classroom because of a drive by councils to reduce exclusions.

"More significant is the inconsistent approach often taken because of the political determination to reduce exclusion figures," she will say.

"It is ridiculous that teachers' ability to teach and pupils' ability to learn can be such a hit-and-miss affair depending on what school they end up in and the support offered by that school in dealing with serious misbehaviour.

"Schools within the same catchment area can have vastly different standards as to what behaviour is tolerated, even condoned."

The SSTA is calling for a consistent approach to dealing with indiscipline, with the acceptance that some behaviour such as violence, threats and verbal abuse of teachers cannot be tolerated.

Previous examples of cyber-bullying include students setting up "hate" groups on social networking sites calling for specific teachers to be sacked.

There are also examples of pupils who have created fake profiles in the names of their teachers containing defamatory information.

One reported case involved a teacher who had a fake Facebook page set up in his name which listed interests that included "underage sex with both boys and girls".

Meanwhile, in his speech to congress, acting general secretary Alan McKenzie said the union would still be considering industrial action on pensions if no future progress was made.

He spoke of the need for teaching unions to work together in future at a time of cuts.

"There is a worrying animosity to teachers out there – much more than in the past – and we must re-position ourselves to withstand the attacks from ... ill-informed parents and out of control youngsters," he said.