A senior teacher who was once embroiled in a race row with Michael Gove has been banned from the class after she hit a vulnerable five-year-old boy.

Kay Johnston, 59, was struck off by a tribunal after she was caught on camera striking the pupil, who has learning difficulties, and knocking him off his chair onto the floor.

She also allowed a teaching assistant to humiliate the child and tie his shoelaces together, a disciplinary hearing was told.

Johnston, from Hither Green in south London, was working as a supply teacher at East Wickham Primary Academy in Welling at the time of the incidents in January 2014.

Struck off: Kay Johnston, left, a teacher who previously clashed with Michael Gove, has been banned from teaching

During her first lesson she struck the child around the head with such force that CCTV footage showed his head and upper body jerk under the weight of the blow.

The same footage also showed the teacher lifting the boy's leg and tipping a chair making him fall to the floor, the National College for Teaching and Learning heard.

Two days later further footage showed Johnston had failed to act when the five-year-old was manhandled throughout the day by various teaching assistants.

On one occasion the boy was spun on his back by his feet and he can also be seen being dragged to his classroom.

The panel also ruled that Johnston acted inappropriately by doing nothing for around two hours after a teaching assistant tied his shoelaces together.

Misconduct: The experienced teacher hit a vulnerable boy and failed to stop a teaching assistant abusing him

A 20-year-old woman received a police caution in the wake of the incident.

Johnston denied any wrongdoing, but the panel's final report read: 'We have carefully and repeatedly viewed the CCTV recording of the alleged "push" and are satisfied on the balance of probabilities that Ms Johnston did push Pupil A off his chair thus causing him to fall to the floor at the relevant time.'

Chairman Gail Goodman added: 'Ms Johnston abused her position of trust in relation to a vulnerable 5 year old child who had complex educational and emotional needs.

'The panel does also take into account his challenging behavioural habits but the psychological effects on Pupil A of Ms Johnston's behaviour are likely to have been significant.

'While Ms Johnston has a previous exemplary history as a teacher over a very long period of time, she has indicated limited insight into her behaviour.'

Incident: The confrontation happened at East Wickham Primary Academy in Welling

Johnston was involved in a high-profile row with the Department for Education under Michael Gove after she was repeatedly denied permission to set up a free school in Lewisham.

One reason given by officials for the rejection was that the school would only serve 'the black community' - prompting furious accusations of racial discrimination.

Johnston said in 2013 that 'there was some degree of discrimination' in the decision, adding: 'It is sad that in Great Britain anyone should feel that the colour of their skin would be an impediment to success.'

She has now been banned from teaching indefinitely after the tribunal ruling, but she can appeal against the judgement within the next four years.

A spokesman for East Wickham Primary Academy said: 'Ms Johnston has not been employed by East Wickham Primary Academy for two years.