Calvin Robinson played a major role in the Department of Education's 'I Chose to Teach campaign, appearing on posters, adverts and online.
But the IT teacher has now come out said pupils were being 'indoctrinated to a left wing mentality' and encouraged to see the Conservative party as 'evil'.
Mr Robinson is head of computer science at St Mary’s and St John’s Church of England School in Hendon, north west London.
Writing on the Conservatives for Liberty website, he said that schools were training kids 'into a lefty way of thinking'.
He wrote: 'Our young people are being indoctrinated to a left-wing mentality from a very young age.
'Pretty much throughout their entire educational career, young people are being trained into a lefty way of thinking.
'I've seen this first hand on too many occasions and it leaves me constantly concerned.
Mr Robinson said pupils were being brainwashed into supporting the Labour Party. Pictured, the teacher during the DoE campaign
'Some of the behaviour I've seen from teachers is outright disgusting - a very evident bias not only in their teaching practices, but in the way they present their arguments.
'I'm not talking about the obvious party political biases of 'Labour = Good, Tory = Evil', although that does happen, but most teachers take a less obvious approach along the lines of tolerance being a good thing, so long as you agree with their way of thinking.'