A teaching union has railed against the practice of teachers devising an individual greeting for each student in their class  - suggesting that it could even leave teachers vulnerable to assault.

The idea has become a global internet phenomenon following a series of viral videos showing teachers greeting their class in this way, but NASUWT teaching union general secretary Chris Keates today blamed this for putting undue pressure on teachers.

Ms Keates believes it is symptomatic of a wider trend that has given school students too much power in schools, to the detriment of teachers.

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Addressing the NASUWT Scotland annual conference in Glasgow today, Ms Keates attacked a number of common school strategies that she believes do not help teachers, including the “meet and greet at the classroom door”.

She said: “Now, in some schools, it’s got to the extreme, and actually there are videos of this up on YouTube [in which] pupils decide which form of meet and greet they want.

“Do they want a handshake? Do they want a high five? Or do they want a hug? And, clearly, the theory must be that the positivity of all of this is going to transcend such minor considerations as the time it takes from your lesson, the safeguarding issues, and the potential for assault arising from unwanted physical contact.”

Ms Keates added: “A teacher from one school actually reported to us that it had taken so long he’d been told to cut his breaktime to accommodate the meet and greet, so that his lessons could actually start on time.”

This type of practice had become more common, she went on, in a climate encouraged by many school leaders, in which “the pupil’s view is often given more weight” than that of teachers.

The #shakeyhandgang and #shakyhandgang hashtags, started by behaviour expert Paul Dix, have been used by teachers to share their experiences of taking up Mr Dix’s pledge to personally welcome their learners into the classroom each day.

One teacher who advocates the practice, Mike Power, tweeted this week that he was “staggered by the lack of understanding shown by some”.

The practice has in the past been advocated in England as a way of improving the exam results of disadvantaged pupils.

A video of US teacher Jerusha Willenborg - in which she goes through the preferred greetings of every child in her class, including clapping, dancing and finger-clicking - has had nearly 7 million views since November 2017.