Prime Minister David Cameron has revealed to pupils at a East Finchley free school that his favourite teacher at Eton College used to throw a “block of wood” at students who did not pay attention in class.

Mr Cameron visited the Archer Academy, in Beaumont Close, this afternoon alongside Mike Freer, Conservative parliamentary candidate for Finchley and Golders Green.

The prime minister was welcomed by headteacher Mick Quigley and took questions from a group of pupils at the school, which opened to an inaugural cohort of Year 7 pupils in September 2013.

Quizzed by pupils on his favourite subject and teacher at school, Mr Cameron said his history teacher at Eton, Michael Kidson, had inspired his love of the subject.

“My favourite teacher was this guy who was so passionate about history,” said Mr Cameron. “But he did have some quite strange tricks which he wouldn’t be able to do now.

“He had a block of wood on his desk and if he caught you napping he would throw this block of wood at your head. Health and safety means you can’t do this anymore!”

Mr Cameron heralded the success of his government’s free school policy during the visit, praising Archer Academy chair of governors Avis Johns for helping to set up the school.

“Not every plan you have in government really works,” he said. “Sometimes you have a great idea and it just gets stuck in the treacle of bureaucracy.

“This one has really flown off the page. So we’ve been the government for five years, I think 500 free schools have been set up or are in the process of being set up and that is pretty quick work.”

The prime minister said constituents should vote for Mr Freer over Labour’s Sarah Sackman to keep the “economy on track” and to prevent “going back to the start with Labour and undoing all the good work”.