Children being taught by 'under-qualified' teachers Pupils taught by staff that lack sufficient knowledge risked being turned off, he suggested. "The absolute essential thing is that a teacher has a good understanding of the subject at the level they are teaching it," he said. Our best indicator of that is holding a degree or post-A-level qualification. Prof Smithers added: "If you have a biologist teaching physics, even at age 11, it may well be that their enthusiasm for physics isn't there, and the child isn't excited by it and moves in another direction. It's the understanding and enthusiasm that's important. He said that schools were still struggling to recruit good staff to teach physics, maths and foreign languages. "Some of the people without degrees teaching these subjects may have been drawn in because of these shortages," Prof Smithers added. Today's figures show that 27.1 per cent of teachers leading maths classes in the current academic year fail to hold a degree in the subject, up from 26 per cent 12 months earlier. In English, 21.7 per cent of teachers - more than 8,400 - failed to have a degree in the subject, compared with 20.4 per cent a year ago. The statistics, which give a snapshot for November last year, also reveal that: Almost 28 per cent of history teachers - around 4,500 in total - do not have a relevant degree-level qualification, up from 24.5 per cent a year earlier; A quarter of chemistry teachers fail to hold a relevant post-A-level qualification; A third - 32.5 per cent - of geography teachers are under-qualified; Numbers are particularly high in foreign languages, with a quarter of French teachers, a third of German teachers and more than half of those teaching Spanish failing to hold a relevant degree; More than half of teachers in other subjects such as religious education and information and communication technology (ICT) were only qualified to A-level standard in their subject. A Department for Education spokeswoman said: "If we want an education system that ranks with the best in the world, we have to attract outstanding people into the profession, and give them excellent training - at the start of - and throughout - their careers." The government is overhauling teacher training and offering better financial bursaries to top science, maths and languages graduates to encourage them to become teachers, she said.