One in five teenagers are now using “Study Tubers” to help them revise for their GCSEs, a survey has found.

Almost a third of children (29 per cent) say that the videos give them social support and reassurance while the worked, according to a poll commissioned by the National Citizen Service (NCS).

These increasingly popular YouTube videos - some of which have been watched millions of times - show teenagers studying for hours on end, while sharing tips and advice about how to revise.

Ruby, whose channel is called Ruby Granger named after her hero Hermione Granger from Harry Potter, has had over 30.8 million views.

Among her videos are speeded-up clips of herself revising for her A-levels in English, Philosophy and Chemistry for 14 and 15 hours a day.

Meanwhile, Jade Bowler’s YouTube channel Unjaded Jade has had more than 25.8 million views - one of her posts shows her crying as she tells how she was rejected from Oxford University - and Eve Bennett from Revision with Eve, has had 13.9 million views.

When parents of GCSE students were asked about Study Tubers, 19 per cent said that their children usually revise while watching the videos.

But four fifths (84 per cent) of parents said they had never heard of Study Tubers, and just over half said they sounded like an excuse not to revise.